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/init.h>
32 #include <linux/sched.h>
33 #include <linux/cpufreq.h>
34 #include <linux/proc_fs.h>
35 #include <linux/seq_file.h>
36 
37 #include <asm/io.h>
38 #include <asm/uaccess.h>
39 
40 #include <acpi/acpi_bus.h>
41 #include <acpi/processor.h>
42 
43 #define ACPI_PROCESSOR_COMPONENT        0x01000000
44 #define ACPI_PROCESSOR_CLASS            "processor"
45 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
46 ACPI_MODULE_NAME("processor_throttling");
47 
48 struct throttling_tstate {
49 	unsigned int cpu;		/* cpu nr */
50 	int target_state;		/* target T-state */
51 };
52 
53 #define THROTTLING_PRECHANGE       (1)
54 #define THROTTLING_POSTCHANGE      (2)
55 
56 static int acpi_processor_get_throttling(struct acpi_processor *pr);
57 int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
58 
59 static int acpi_processor_update_tsd_coord(void)
60 {
61 	int count, count_target;
62 	int retval = 0;
63 	unsigned int i, j;
64 	cpumask_t covered_cpus;
65 	struct acpi_processor *pr, *match_pr;
66 	struct acpi_tsd_package *pdomain, *match_pdomain;
67 	struct acpi_processor_throttling *pthrottling, *match_pthrottling;
68 
69 	/*
70 	 * Now that we have _TSD data from all CPUs, lets setup T-state
71 	 * coordination between all CPUs.
72 	 */
73 	for_each_possible_cpu(i) {
74 		pr = processors[i];
75 		if (!pr)
76 			continue;
77 
78 		/* Basic validity check for domain info */
79 		pthrottling = &(pr->throttling);
80 
81 		/*
82 		 * If tsd package for one cpu is invalid, the coordination
83 		 * among all CPUs is thought as invalid.
84 		 * Maybe it is ugly.
85 		 */
86 		if (!pthrottling->tsd_valid_flag) {
87 			retval = -EINVAL;
88 			break;
89 		}
90 	}
91 	if (retval)
92 		goto err_ret;
93 
94 	cpus_clear(covered_cpus);
95 	for_each_possible_cpu(i) {
96 		pr = processors[i];
97 		if (!pr)
98 			continue;
99 
100 		if (cpu_isset(i, covered_cpus))
101 			continue;
102 		pthrottling = &pr->throttling;
103 
104 		pdomain = &(pthrottling->domain_info);
105 		cpu_set(i, pthrottling->shared_cpu_map);
106 		cpu_set(i, covered_cpus);
107 		/*
108 		 * If the number of processor in the TSD domain is 1, it is
109 		 * unnecessary to parse the coordination for this CPU.
110 		 */
111 		if (pdomain->num_processors <= 1)
112 			continue;
113 
114 		/* Validate the Domain info */
115 		count_target = pdomain->num_processors;
116 		count = 1;
117 
118 		for_each_possible_cpu(j) {
119 			if (i == j)
120 				continue;
121 
122 			match_pr = processors[j];
123 			if (!match_pr)
124 				continue;
125 
126 			match_pthrottling = &(match_pr->throttling);
127 			match_pdomain = &(match_pthrottling->domain_info);
128 			if (match_pdomain->domain != pdomain->domain)
129 				continue;
130 
131 			/* Here i and j are in the same domain.
132 			 * If two TSD packages have the same domain, they
133 			 * should have the same num_porcessors and
134 			 * coordination type. Otherwise it will be regarded
135 			 * as illegal.
136 			 */
137 			if (match_pdomain->num_processors != count_target) {
138 				retval = -EINVAL;
139 				goto err_ret;
140 			}
141 
142 			if (pdomain->coord_type != match_pdomain->coord_type) {
143 				retval = -EINVAL;
144 				goto err_ret;
145 			}
146 
147 			cpu_set(j, covered_cpus);
148 			cpu_set(j, pthrottling->shared_cpu_map);
149 			count++;
150 		}
151 		for_each_possible_cpu(j) {
152 			if (i == j)
153 				continue;
154 
155 			match_pr = processors[j];
156 			if (!match_pr)
157 				continue;
158 
159 			match_pthrottling = &(match_pr->throttling);
160 			match_pdomain = &(match_pthrottling->domain_info);
161 			if (match_pdomain->domain != pdomain->domain)
162 				continue;
163 
164 			/*
165 			 * If some CPUS have the same domain, they
166 			 * will have the same shared_cpu_map.
167 			 */
168 			match_pthrottling->shared_cpu_map =
169 				pthrottling->shared_cpu_map;
170 		}
171 	}
172 
173 err_ret:
174 	for_each_possible_cpu(i) {
175 		pr = 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 			cpus_clear(pthrottling->shared_cpu_map);
186 			cpu_set(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 	return;
205 }
206 
207 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
208 {
209 	struct throttling_tstate *p_tstate = data;
210 	struct acpi_processor *pr;
211 	unsigned int cpu ;
212 	int target_state;
213 	struct acpi_processor_limit *p_limit;
214 	struct acpi_processor_throttling *p_throttling;
215 
216 	cpu = p_tstate->cpu;
217 	pr = processors[cpu];
218 	if (!pr) {
219 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
220 		return 0;
221 	}
222 	if (!pr->flags.throttling) {
223 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
224 				"unsupported on CPU %d\n", cpu));
225 		return 0;
226 	}
227 	target_state = p_tstate->target_state;
228 	p_throttling = &(pr->throttling);
229 	switch (event) {
230 	case THROTTLING_PRECHANGE:
231 		/*
232 		 * Prechange event is used to choose one proper t-state,
233 		 * which meets the limits of thermal, user and _TPC.
234 		 */
235 		p_limit = &pr->limit;
236 		if (p_limit->thermal.tx > target_state)
237 			target_state = p_limit->thermal.tx;
238 		if (p_limit->user.tx > target_state)
239 			target_state = p_limit->user.tx;
240 		if (pr->throttling_platform_limit > target_state)
241 			target_state = pr->throttling_platform_limit;
242 		if (target_state >= p_throttling->state_count) {
243 			printk(KERN_WARNING
244 				"Exceed the limit of T-state \n");
245 			target_state = p_throttling->state_count - 1;
246 		}
247 		p_tstate->target_state = target_state;
248 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
249 				"target T-state of CPU %d is T%d\n",
250 				cpu, target_state));
251 		break;
252 	case THROTTLING_POSTCHANGE:
253 		/*
254 		 * Postchange event is only used to update the
255 		 * T-state flag of acpi_processor_throttling.
256 		 */
257 		p_throttling->state = target_state;
258 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
259 				"CPU %d is switched to T%d\n",
260 				cpu, target_state));
261 		break;
262 	default:
263 		printk(KERN_WARNING
264 			"Unsupported Throttling notifier event\n");
265 		break;
266 	}
267 
268 	return 0;
269 }
270 
271 /*
272  * _TPC - Throttling Present Capabilities
273  */
274 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
275 {
276 	acpi_status status = 0;
277 	unsigned long tpc = 0;
278 
279 	if (!pr)
280 		return -EINVAL;
281 	status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
282 	if (ACPI_FAILURE(status)) {
283 		if (status != AE_NOT_FOUND) {
284 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
285 		}
286 		return -ENODEV;
287 	}
288 	pr->throttling_platform_limit = (int)tpc;
289 	return 0;
290 }
291 
292 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
293 {
294 	int result = 0;
295 	int throttling_limit;
296 	int current_state;
297 	struct acpi_processor_limit *limit;
298 	int target_state;
299 
300 	result = acpi_processor_get_platform_limit(pr);
301 	if (result) {
302 		/* Throttling Limit is unsupported */
303 		return result;
304 	}
305 
306 	throttling_limit = pr->throttling_platform_limit;
307 	if (throttling_limit >= pr->throttling.state_count) {
308 		/* Uncorrect Throttling Limit */
309 		return -EINVAL;
310 	}
311 
312 	current_state = pr->throttling.state;
313 	if (current_state > throttling_limit) {
314 		/*
315 		 * The current state can meet the requirement of
316 		 * _TPC limit. But it is reasonable that OSPM changes
317 		 * t-states from high to low for better performance.
318 		 * Of course the limit condition of thermal
319 		 * and user should be considered.
320 		 */
321 		limit = &pr->limit;
322 		target_state = throttling_limit;
323 		if (limit->thermal.tx > target_state)
324 			target_state = limit->thermal.tx;
325 		if (limit->user.tx > target_state)
326 			target_state = limit->user.tx;
327 	} else if (current_state == throttling_limit) {
328 		/*
329 		 * Unnecessary to change the throttling state
330 		 */
331 		return 0;
332 	} else {
333 		/*
334 		 * If the current state is lower than the limit of _TPC, it
335 		 * will be forced to switch to the throttling state defined
336 		 * by throttling_platfor_limit.
337 		 * Because the previous state meets with the limit condition
338 		 * of thermal and user, it is unnecessary to check it again.
339 		 */
340 		target_state = throttling_limit;
341 	}
342 	return acpi_processor_set_throttling(pr, target_state);
343 }
344 
345 /*
346  * _PTC - Processor Throttling Control (and status) register location
347  */
348 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
349 {
350 	int result = 0;
351 	acpi_status status = 0;
352 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
353 	union acpi_object *ptc = NULL;
354 	union acpi_object obj = { 0 };
355 	struct acpi_processor_throttling *throttling;
356 
357 	status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
358 	if (ACPI_FAILURE(status)) {
359 		if (status != AE_NOT_FOUND) {
360 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
361 		}
362 		return -ENODEV;
363 	}
364 
365 	ptc = (union acpi_object *)buffer.pointer;
366 	if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
367 	    || (ptc->package.count != 2)) {
368 		printk(KERN_ERR PREFIX "Invalid _PTC data\n");
369 		result = -EFAULT;
370 		goto end;
371 	}
372 
373 	/*
374 	 * control_register
375 	 */
376 
377 	obj = ptc->package.elements[0];
378 
379 	if ((obj.type != ACPI_TYPE_BUFFER)
380 	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
381 	    || (obj.buffer.pointer == NULL)) {
382 		printk(KERN_ERR PREFIX
383 		       "Invalid _PTC data (control_register)\n");
384 		result = -EFAULT;
385 		goto end;
386 	}
387 	memcpy(&pr->throttling.control_register, obj.buffer.pointer,
388 	       sizeof(struct acpi_ptc_register));
389 
390 	/*
391 	 * status_register
392 	 */
393 
394 	obj = ptc->package.elements[1];
395 
396 	if ((obj.type != ACPI_TYPE_BUFFER)
397 	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
398 	    || (obj.buffer.pointer == NULL)) {
399 		printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
400 		result = -EFAULT;
401 		goto end;
402 	}
403 
404 	memcpy(&pr->throttling.status_register, obj.buffer.pointer,
405 	       sizeof(struct acpi_ptc_register));
406 
407 	throttling = &pr->throttling;
408 
409 	if ((throttling->control_register.bit_width +
410 		throttling->control_register.bit_offset) > 32) {
411 		printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
412 		result = -EFAULT;
413 		goto end;
414 	}
415 
416 	if ((throttling->status_register.bit_width +
417 		throttling->status_register.bit_offset) > 32) {
418 		printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
419 		result = -EFAULT;
420 		goto end;
421 	}
422 
423       end:
424 	kfree(buffer.pointer);
425 
426 	return result;
427 }
428 
429 /*
430  * _TSS - Throttling Supported States
431  */
432 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
433 {
434 	int result = 0;
435 	acpi_status status = AE_OK;
436 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
437 	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
438 	struct acpi_buffer state = { 0, NULL };
439 	union acpi_object *tss = NULL;
440 	int i;
441 
442 	status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
443 	if (ACPI_FAILURE(status)) {
444 		if (status != AE_NOT_FOUND) {
445 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
446 		}
447 		return -ENODEV;
448 	}
449 
450 	tss = buffer.pointer;
451 	if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
452 		printk(KERN_ERR PREFIX "Invalid _TSS data\n");
453 		result = -EFAULT;
454 		goto end;
455 	}
456 
457 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
458 			  tss->package.count));
459 
460 	pr->throttling.state_count = tss->package.count;
461 	pr->throttling.states_tss =
462 	    kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
463 		    GFP_KERNEL);
464 	if (!pr->throttling.states_tss) {
465 		result = -ENOMEM;
466 		goto end;
467 	}
468 
469 	for (i = 0; i < pr->throttling.state_count; i++) {
470 
471 		struct acpi_processor_tx_tss *tx =
472 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
473 						      states_tss[i]);
474 
475 		state.length = sizeof(struct acpi_processor_tx_tss);
476 		state.pointer = tx;
477 
478 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
479 
480 		status = acpi_extract_package(&(tss->package.elements[i]),
481 					      &format, &state);
482 		if (ACPI_FAILURE(status)) {
483 			ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
484 			result = -EFAULT;
485 			kfree(pr->throttling.states_tss);
486 			goto end;
487 		}
488 
489 		if (!tx->freqpercentage) {
490 			printk(KERN_ERR PREFIX
491 			       "Invalid _TSS data: freq is zero\n");
492 			result = -EFAULT;
493 			kfree(pr->throttling.states_tss);
494 			goto end;
495 		}
496 	}
497 
498       end:
499 	kfree(buffer.pointer);
500 
501 	return result;
502 }
503 
504 /*
505  * _TSD - T-State Dependencies
506  */
507 static int acpi_processor_get_tsd(struct acpi_processor *pr)
508 {
509 	int result = 0;
510 	acpi_status status = AE_OK;
511 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
512 	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
513 	struct acpi_buffer state = { 0, NULL };
514 	union acpi_object *tsd = NULL;
515 	struct acpi_tsd_package *pdomain;
516 	struct acpi_processor_throttling *pthrottling;
517 
518 	pthrottling = &pr->throttling;
519 	pthrottling->tsd_valid_flag = 0;
520 
521 	status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
522 	if (ACPI_FAILURE(status)) {
523 		if (status != AE_NOT_FOUND) {
524 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
525 		}
526 		return -ENODEV;
527 	}
528 
529 	tsd = buffer.pointer;
530 	if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
531 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
532 		result = -EFAULT;
533 		goto end;
534 	}
535 
536 	if (tsd->package.count != 1) {
537 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
538 		result = -EFAULT;
539 		goto end;
540 	}
541 
542 	pdomain = &(pr->throttling.domain_info);
543 
544 	state.length = sizeof(struct acpi_tsd_package);
545 	state.pointer = pdomain;
546 
547 	status = acpi_extract_package(&(tsd->package.elements[0]),
548 				      &format, &state);
549 	if (ACPI_FAILURE(status)) {
550 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
551 		result = -EFAULT;
552 		goto end;
553 	}
554 
555 	if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
556 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:num_entries\n"));
557 		result = -EFAULT;
558 		goto end;
559 	}
560 
561 	if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
562 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:revision\n"));
563 		result = -EFAULT;
564 		goto end;
565 	}
566 
567 	pthrottling = &pr->throttling;
568 	pthrottling->tsd_valid_flag = 1;
569 	pthrottling->shared_type = pdomain->coord_type;
570 	cpu_set(pr->id, pthrottling->shared_cpu_map);
571 	/*
572 	 * If the coordination type is not defined in ACPI spec,
573 	 * the tsd_valid_flag will be clear and coordination type
574 	 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
575 	 */
576 	if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
577 		pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
578 		pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
579 		pthrottling->tsd_valid_flag = 0;
580 		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
581 	}
582 
583       end:
584 	kfree(buffer.pointer);
585 	return result;
586 }
587 
588 /* --------------------------------------------------------------------------
589                               Throttling Control
590    -------------------------------------------------------------------------- */
591 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
592 {
593 	int state = 0;
594 	u32 value = 0;
595 	u32 duty_mask = 0;
596 	u32 duty_value = 0;
597 
598 	if (!pr)
599 		return -EINVAL;
600 
601 	if (!pr->flags.throttling)
602 		return -ENODEV;
603 
604 	pr->throttling.state = 0;
605 
606 	duty_mask = pr->throttling.state_count - 1;
607 
608 	duty_mask <<= pr->throttling.duty_offset;
609 
610 	local_irq_disable();
611 
612 	value = inl(pr->throttling.address);
613 
614 	/*
615 	 * Compute the current throttling state when throttling is enabled
616 	 * (bit 4 is on).
617 	 */
618 	if (value & 0x10) {
619 		duty_value = value & duty_mask;
620 		duty_value >>= pr->throttling.duty_offset;
621 
622 		if (duty_value)
623 			state = pr->throttling.state_count - duty_value;
624 	}
625 
626 	pr->throttling.state = state;
627 
628 	local_irq_enable();
629 
630 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
631 			  "Throttling state is T%d (%d%% throttling applied)\n",
632 			  state, pr->throttling.states[state].performance));
633 
634 	return 0;
635 }
636 
637 #ifdef CONFIG_X86
638 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
639 					acpi_integer * value)
640 {
641 	struct cpuinfo_x86 *c;
642 	u64 msr_high, msr_low;
643 	unsigned int cpu;
644 	u64 msr = 0;
645 	int ret = -1;
646 
647 	cpu = pr->id;
648 	c = &cpu_data(cpu);
649 
650 	if ((c->x86_vendor != X86_VENDOR_INTEL) ||
651 		!cpu_has(c, X86_FEATURE_ACPI)) {
652 		printk(KERN_ERR PREFIX
653 			"HARDWARE addr space,NOT supported yet\n");
654 	} else {
655 		msr_low = 0;
656 		msr_high = 0;
657 		rdmsr_safe(MSR_IA32_THERM_CONTROL,
658 			(u32 *)&msr_low , (u32 *) &msr_high);
659 		msr = (msr_high << 32) | msr_low;
660 		*value = (acpi_integer) msr;
661 		ret = 0;
662 	}
663 	return ret;
664 }
665 
666 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
667 {
668 	struct cpuinfo_x86 *c;
669 	unsigned int cpu;
670 	int ret = -1;
671 	u64 msr;
672 
673 	cpu = pr->id;
674 	c = &cpu_data(cpu);
675 
676 	if ((c->x86_vendor != X86_VENDOR_INTEL) ||
677 		!cpu_has(c, X86_FEATURE_ACPI)) {
678 		printk(KERN_ERR PREFIX
679 			"HARDWARE addr space,NOT supported yet\n");
680 	} else {
681 		msr = value;
682 		wrmsr_safe(MSR_IA32_THERM_CONTROL,
683 			msr & 0xffffffff, msr >> 32);
684 		ret = 0;
685 	}
686 	return ret;
687 }
688 #else
689 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
690 				acpi_integer * value)
691 {
692 	printk(KERN_ERR PREFIX
693 		"HARDWARE addr space,NOT supported yet\n");
694 	return -1;
695 }
696 
697 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
698 {
699 	printk(KERN_ERR PREFIX
700 		"HARDWARE addr space,NOT supported yet\n");
701 	return -1;
702 }
703 #endif
704 
705 static int acpi_read_throttling_status(struct acpi_processor *pr,
706 					acpi_integer *value)
707 {
708 	u32 bit_width, bit_offset;
709 	u64 ptc_value;
710 	u64 ptc_mask;
711 	struct acpi_processor_throttling *throttling;
712 	int ret = -1;
713 
714 	throttling = &pr->throttling;
715 	switch (throttling->status_register.space_id) {
716 	case ACPI_ADR_SPACE_SYSTEM_IO:
717 		ptc_value = 0;
718 		bit_width = throttling->status_register.bit_width;
719 		bit_offset = throttling->status_register.bit_offset;
720 
721 		acpi_os_read_port((acpi_io_address) throttling->status_register.
722 				  address, (u32 *) &ptc_value,
723 				  (u32) (bit_width + bit_offset));
724 		ptc_mask = (1 << bit_width) - 1;
725 		*value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask);
726 		ret = 0;
727 		break;
728 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
729 		ret = acpi_throttling_rdmsr(pr, value);
730 		break;
731 	default:
732 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
733 		       (u32) (throttling->status_register.space_id));
734 	}
735 	return ret;
736 }
737 
738 static int acpi_write_throttling_state(struct acpi_processor *pr,
739 				acpi_integer value)
740 {
741 	u32 bit_width, bit_offset;
742 	u64 ptc_value;
743 	u64 ptc_mask;
744 	struct acpi_processor_throttling *throttling;
745 	int ret = -1;
746 
747 	throttling = &pr->throttling;
748 	switch (throttling->control_register.space_id) {
749 	case ACPI_ADR_SPACE_SYSTEM_IO:
750 		bit_width = throttling->control_register.bit_width;
751 		bit_offset = throttling->control_register.bit_offset;
752 		ptc_mask = (1 << bit_width) - 1;
753 		ptc_value = value & ptc_mask;
754 
755 		acpi_os_write_port((acpi_io_address) throttling->
756 					control_register.address,
757 					(u32) (ptc_value << bit_offset),
758 					(u32) (bit_width + bit_offset));
759 		ret = 0;
760 		break;
761 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
762 		ret = acpi_throttling_wrmsr(pr, value);
763 		break;
764 	default:
765 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
766 		       (u32) (throttling->control_register.space_id));
767 	}
768 	return ret;
769 }
770 
771 static int acpi_get_throttling_state(struct acpi_processor *pr,
772 				acpi_integer value)
773 {
774 	int i;
775 
776 	for (i = 0; i < pr->throttling.state_count; i++) {
777 		struct acpi_processor_tx_tss *tx =
778 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
779 						      states_tss[i]);
780 		if (tx->control == value)
781 			break;
782 	}
783 	if (i > pr->throttling.state_count)
784 		i = -1;
785 	return i;
786 }
787 
788 static int acpi_get_throttling_value(struct acpi_processor *pr,
789 			int state, acpi_integer *value)
790 {
791 	int ret = -1;
792 
793 	if (state >= 0 && state <= pr->throttling.state_count) {
794 		struct acpi_processor_tx_tss *tx =
795 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
796 						      states_tss[state]);
797 		*value = tx->control;
798 		ret = 0;
799 	}
800 	return ret;
801 }
802 
803 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
804 {
805 	int state = 0;
806 	int ret;
807 	acpi_integer value;
808 
809 	if (!pr)
810 		return -EINVAL;
811 
812 	if (!pr->flags.throttling)
813 		return -ENODEV;
814 
815 	pr->throttling.state = 0;
816 
817 	value = 0;
818 	ret = acpi_read_throttling_status(pr, &value);
819 	if (ret >= 0) {
820 		state = acpi_get_throttling_state(pr, value);
821 		pr->throttling.state = state;
822 	}
823 
824 	return 0;
825 }
826 
827 static int acpi_processor_get_throttling(struct acpi_processor *pr)
828 {
829 	cpumask_t saved_mask;
830 	int ret;
831 
832 	if (!pr)
833 		return -EINVAL;
834 
835 	if (!pr->flags.throttling)
836 		return -ENODEV;
837 	/*
838 	 * Migrate task to the cpu pointed by pr.
839 	 */
840 	saved_mask = current->cpus_allowed;
841 	set_cpus_allowed_ptr(current, &cpumask_of_cpu(pr->id));
842 	ret = pr->throttling.acpi_processor_get_throttling(pr);
843 	/* restore the previous state */
844 	set_cpus_allowed_ptr(current, &saved_mask);
845 
846 	return ret;
847 }
848 
849 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
850 {
851 	int i, step;
852 
853 	if (!pr->throttling.address) {
854 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
855 		return -EINVAL;
856 	} else if (!pr->throttling.duty_width) {
857 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
858 		return -EINVAL;
859 	}
860 	/* TBD: Support duty_cycle values that span bit 4. */
861 	else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
862 		printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
863 		return -EINVAL;
864 	}
865 
866 	pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
867 
868 	/*
869 	 * Compute state values. Note that throttling displays a linear power
870 	 * performance relationship (at 50% performance the CPU will consume
871 	 * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
872 	 */
873 
874 	step = (1000 / pr->throttling.state_count);
875 
876 	for (i = 0; i < pr->throttling.state_count; i++) {
877 		pr->throttling.states[i].performance = 1000 - step * i;
878 		pr->throttling.states[i].power = 1000 - step * i;
879 	}
880 	return 0;
881 }
882 
883 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
884 					      int state)
885 {
886 	u32 value = 0;
887 	u32 duty_mask = 0;
888 	u32 duty_value = 0;
889 
890 	if (!pr)
891 		return -EINVAL;
892 
893 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
894 		return -EINVAL;
895 
896 	if (!pr->flags.throttling)
897 		return -ENODEV;
898 
899 	if (state == pr->throttling.state)
900 		return 0;
901 
902 	if (state < pr->throttling_platform_limit)
903 		return -EPERM;
904 	/*
905 	 * Calculate the duty_value and duty_mask.
906 	 */
907 	if (state) {
908 		duty_value = pr->throttling.state_count - state;
909 
910 		duty_value <<= pr->throttling.duty_offset;
911 
912 		/* Used to clear all duty_value bits */
913 		duty_mask = pr->throttling.state_count - 1;
914 
915 		duty_mask <<= acpi_gbl_FADT.duty_offset;
916 		duty_mask = ~duty_mask;
917 	}
918 
919 	local_irq_disable();
920 
921 	/*
922 	 * Disable throttling by writing a 0 to bit 4.  Note that we must
923 	 * turn it off before you can change the duty_value.
924 	 */
925 	value = inl(pr->throttling.address);
926 	if (value & 0x10) {
927 		value &= 0xFFFFFFEF;
928 		outl(value, pr->throttling.address);
929 	}
930 
931 	/*
932 	 * Write the new duty_value and then enable throttling.  Note
933 	 * that a state value of 0 leaves throttling disabled.
934 	 */
935 	if (state) {
936 		value &= duty_mask;
937 		value |= duty_value;
938 		outl(value, pr->throttling.address);
939 
940 		value |= 0x00000010;
941 		outl(value, pr->throttling.address);
942 	}
943 
944 	pr->throttling.state = state;
945 
946 	local_irq_enable();
947 
948 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
949 			  "Throttling state set to T%d (%d%%)\n", state,
950 			  (pr->throttling.states[state].performance ? pr->
951 			   throttling.states[state].performance / 10 : 0)));
952 
953 	return 0;
954 }
955 
956 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
957 					     int state)
958 {
959 	int ret;
960 	acpi_integer value;
961 
962 	if (!pr)
963 		return -EINVAL;
964 
965 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
966 		return -EINVAL;
967 
968 	if (!pr->flags.throttling)
969 		return -ENODEV;
970 
971 	if (state == pr->throttling.state)
972 		return 0;
973 
974 	if (state < pr->throttling_platform_limit)
975 		return -EPERM;
976 
977 	value = 0;
978 	ret = acpi_get_throttling_value(pr, state, &value);
979 	if (ret >= 0) {
980 		acpi_write_throttling_state(pr, value);
981 		pr->throttling.state = state;
982 	}
983 
984 	return 0;
985 }
986 
987 int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
988 {
989 	cpumask_t saved_mask;
990 	int ret = 0;
991 	unsigned int i;
992 	struct acpi_processor *match_pr;
993 	struct acpi_processor_throttling *p_throttling;
994 	struct throttling_tstate t_state;
995 	cpumask_t online_throttling_cpus;
996 
997 	if (!pr)
998 		return -EINVAL;
999 
1000 	if (!pr->flags.throttling)
1001 		return -ENODEV;
1002 
1003 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1004 		return -EINVAL;
1005 
1006 	saved_mask = current->cpus_allowed;
1007 	t_state.target_state = state;
1008 	p_throttling = &(pr->throttling);
1009 	cpus_and(online_throttling_cpus, cpu_online_map,
1010 			p_throttling->shared_cpu_map);
1011 	/*
1012 	 * The throttling notifier will be called for every
1013 	 * affected cpu in order to get one proper T-state.
1014 	 * The notifier event is THROTTLING_PRECHANGE.
1015 	 */
1016 	for_each_cpu_mask(i, online_throttling_cpus) {
1017 		t_state.cpu = i;
1018 		acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1019 							&t_state);
1020 	}
1021 	/*
1022 	 * The function of acpi_processor_set_throttling will be called
1023 	 * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1024 	 * it is necessary to call it for every affected cpu. Otherwise
1025 	 * it can be called only for the cpu pointed by pr.
1026 	 */
1027 	if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1028 		set_cpus_allowed_ptr(current, &cpumask_of_cpu(pr->id));
1029 		ret = p_throttling->acpi_processor_set_throttling(pr,
1030 						t_state.target_state);
1031 	} else {
1032 		/*
1033 		 * When the T-state coordination is SW_ALL or HW_ALL,
1034 		 * it is necessary to set T-state for every affected
1035 		 * cpus.
1036 		 */
1037 		for_each_cpu_mask(i, online_throttling_cpus) {
1038 			match_pr = processors[i];
1039 			/*
1040 			 * If the pointer is invalid, we will report the
1041 			 * error message and continue.
1042 			 */
1043 			if (!match_pr) {
1044 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1045 					"Invalid Pointer for CPU %d\n", i));
1046 				continue;
1047 			}
1048 			/*
1049 			 * If the throttling control is unsupported on CPU i,
1050 			 * we will report the error message and continue.
1051 			 */
1052 			if (!match_pr->flags.throttling) {
1053 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1054 					"Throttling Controll is unsupported "
1055 					"on CPU %d\n", i));
1056 				continue;
1057 			}
1058 			t_state.cpu = i;
1059 			set_cpus_allowed_ptr(current, &cpumask_of_cpu(i));
1060 			ret = match_pr->throttling.
1061 				acpi_processor_set_throttling(
1062 				match_pr, t_state.target_state);
1063 		}
1064 	}
1065 	/*
1066 	 * After the set_throttling is called, the
1067 	 * throttling notifier is called for every
1068 	 * affected cpu to update the T-states.
1069 	 * The notifier event is THROTTLING_POSTCHANGE
1070 	 */
1071 	for_each_cpu_mask(i, online_throttling_cpus) {
1072 		t_state.cpu = i;
1073 		acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1074 							&t_state);
1075 	}
1076 	/* restore the previous state */
1077 	set_cpus_allowed_ptr(current, &saved_mask);
1078 	return ret;
1079 }
1080 
1081 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1082 {
1083 	int result = 0;
1084 	struct acpi_processor_throttling *pthrottling;
1085 
1086 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1087 			  "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1088 			  pr->throttling.address,
1089 			  pr->throttling.duty_offset,
1090 			  pr->throttling.duty_width));
1091 
1092 	if (!pr)
1093 		return -EINVAL;
1094 
1095 	/*
1096 	 * Evaluate _PTC, _TSS and _TPC
1097 	 * They must all be present or none of them can be used.
1098 	 */
1099 	if (acpi_processor_get_throttling_control(pr) ||
1100 		acpi_processor_get_throttling_states(pr) ||
1101 		acpi_processor_get_platform_limit(pr))
1102 	{
1103 		pr->throttling.acpi_processor_get_throttling =
1104 		    &acpi_processor_get_throttling_fadt;
1105 		pr->throttling.acpi_processor_set_throttling =
1106 		    &acpi_processor_set_throttling_fadt;
1107 		if (acpi_processor_get_fadt_info(pr))
1108 			return 0;
1109 	} else {
1110 		pr->throttling.acpi_processor_get_throttling =
1111 		    &acpi_processor_get_throttling_ptc;
1112 		pr->throttling.acpi_processor_set_throttling =
1113 		    &acpi_processor_set_throttling_ptc;
1114 	}
1115 
1116 	/*
1117 	 * If TSD package for one CPU can't be parsed successfully, it means
1118 	 * that this CPU will have no coordination with other CPUs.
1119 	 */
1120 	if (acpi_processor_get_tsd(pr)) {
1121 		pthrottling = &pr->throttling;
1122 		pthrottling->tsd_valid_flag = 0;
1123 		cpu_set(pr->id, pthrottling->shared_cpu_map);
1124 		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1125 	}
1126 
1127 	/*
1128 	 * PIIX4 Errata: We don't support throttling on the original PIIX4.
1129 	 * This shouldn't be an issue as few (if any) mobile systems ever
1130 	 * used this part.
1131 	 */
1132 	if (errata.piix4.throttle) {
1133 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1134 				  "Throttling not supported on PIIX4 A- or B-step\n"));
1135 		return 0;
1136 	}
1137 
1138 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1139 			  pr->throttling.state_count));
1140 
1141 	pr->flags.throttling = 1;
1142 
1143 	/*
1144 	 * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1145 	 * thermal) decide to lower performance if it so chooses, but for now
1146 	 * we'll crank up the speed.
1147 	 */
1148 
1149 	result = acpi_processor_get_throttling(pr);
1150 	if (result)
1151 		goto end;
1152 
1153 	if (pr->throttling.state) {
1154 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1155 				  "Disabling throttling (was T%d)\n",
1156 				  pr->throttling.state));
1157 		result = acpi_processor_set_throttling(pr, 0);
1158 		if (result)
1159 			goto end;
1160 	}
1161 
1162       end:
1163 	if (result)
1164 		pr->flags.throttling = 0;
1165 
1166 	return result;
1167 }
1168 
1169 /* proc interface */
1170 
1171 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1172 					      void *offset)
1173 {
1174 	struct acpi_processor *pr = seq->private;
1175 	int i = 0;
1176 	int result = 0;
1177 
1178 	if (!pr)
1179 		goto end;
1180 
1181 	if (!(pr->throttling.state_count > 0)) {
1182 		seq_puts(seq, "<not supported>\n");
1183 		goto end;
1184 	}
1185 
1186 	result = acpi_processor_get_throttling(pr);
1187 
1188 	if (result) {
1189 		seq_puts(seq,
1190 			 "Could not determine current throttling state.\n");
1191 		goto end;
1192 	}
1193 
1194 	seq_printf(seq, "state count:             %d\n"
1195 		   "active state:            T%d\n"
1196 		   "state available: T%d to T%d\n",
1197 		   pr->throttling.state_count, pr->throttling.state,
1198 		   pr->throttling_platform_limit,
1199 		   pr->throttling.state_count - 1);
1200 
1201 	seq_puts(seq, "states:\n");
1202 	if (pr->throttling.acpi_processor_get_throttling ==
1203 			acpi_processor_get_throttling_fadt) {
1204 		for (i = 0; i < pr->throttling.state_count; i++)
1205 			seq_printf(seq, "   %cT%d:                  %02d%%\n",
1206 				   (i == pr->throttling.state ? '*' : ' '), i,
1207 				   (pr->throttling.states[i].performance ? pr->
1208 				    throttling.states[i].performance / 10 : 0));
1209 	} else {
1210 		for (i = 0; i < pr->throttling.state_count; i++)
1211 			seq_printf(seq, "   %cT%d:                  %02d%%\n",
1212 				   (i == pr->throttling.state ? '*' : ' '), i,
1213 				   (int)pr->throttling.states_tss[i].
1214 				   freqpercentage);
1215 	}
1216 
1217       end:
1218 	return 0;
1219 }
1220 
1221 static int acpi_processor_throttling_open_fs(struct inode *inode,
1222 					     struct file *file)
1223 {
1224 	return single_open(file, acpi_processor_throttling_seq_show,
1225 			   PDE(inode)->data);
1226 }
1227 
1228 static ssize_t acpi_processor_write_throttling(struct file *file,
1229 					       const char __user * buffer,
1230 					       size_t count, loff_t * data)
1231 {
1232 	int result = 0;
1233 	struct seq_file *m = file->private_data;
1234 	struct acpi_processor *pr = m->private;
1235 	char state_string[12] = { '\0' };
1236 
1237 	if (!pr || (count > sizeof(state_string) - 1))
1238 		return -EINVAL;
1239 
1240 	if (copy_from_user(state_string, buffer, count))
1241 		return -EFAULT;
1242 
1243 	state_string[count] = '\0';
1244 
1245 	result = acpi_processor_set_throttling(pr,
1246 					       simple_strtoul(state_string,
1247 							      NULL, 0));
1248 	if (result)
1249 		return result;
1250 
1251 	return count;
1252 }
1253 
1254 struct file_operations acpi_processor_throttling_fops = {
1255 	.owner = THIS_MODULE,
1256 	.open = acpi_processor_throttling_open_fs,
1257 	.read = seq_read,
1258 	.write = acpi_processor_write_throttling,
1259 	.llseek = seq_lseek,
1260 	.release = single_release,
1261 };
1262