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(current, cpumask_of_cpu(pr->id));
842 ret = pr->throttling.acpi_processor_get_throttling(pr);
843 /* restore the previous state */
844 set_cpus_allowed(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(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(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(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 .open = acpi_processor_throttling_open_fs,
1256 .read = seq_read,
1257 .write = acpi_processor_write_throttling,
1258 .llseek = seq_lseek,
1259 .release = single_release,
1260 };
1261
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