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added 2.6.29.6 aldebaran kernel
[nao-ulib.git] / kernel / 2.6.29.6-aldebaran-rt / drivers / acpi / processor_throttling.c
blobd27838171f4ad2b48dcfc916a1c2cc31e92b721f
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/acpi_drivers.h>
42 #include <acpi/processor.h>
43
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_var_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 if (!alloc_cpumask_var(&covered_cpus, GFP_KERNEL))
70 return -ENOMEM;
71
72 /*
73 * Now that we have _TSD data from all CPUs, lets setup T-state
74 * coordination between all CPUs.
75 */
76 for_each_possible_cpu(i) {
77 pr = per_cpu(processors, i);
78 if (!pr)
79 continue;
80
81 /* Basic validity check for domain info */
82 pthrottling = &(pr->throttling);
83
84 /*
85 * If tsd package for one cpu is invalid, the coordination
86 * among all CPUs is thought as invalid.
87 * Maybe it is ugly.
88 */
89 if (!pthrottling->tsd_valid_flag) {
90 retval = -EINVAL;
91 break;
92 }
93 }
94 if (retval)
95 goto err_ret;
96
97 cpumask_clear(covered_cpus);
98 for_each_possible_cpu(i) {
99 pr = per_cpu(processors, i);
100 if (!pr)
101 continue;
102
103 if (cpumask_test_cpu(i, covered_cpus))
104 continue;
105 pthrottling = &pr->throttling;
106
107 pdomain = &(pthrottling->domain_info);
108 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
109 cpumask_set_cpu(i, covered_cpus);
110 /*
111 * If the number of processor in the TSD domain is 1, it is
112 * unnecessary to parse the coordination for this CPU.
113 */
114 if (pdomain->num_processors <= 1)
115 continue;
116
117 /* Validate the Domain info */
118 count_target = pdomain->num_processors;
119 count = 1;
120
121 for_each_possible_cpu(j) {
122 if (i == j)
123 continue;
124
125 match_pr = per_cpu(processors, j);
126 if (!match_pr)
127 continue;
128
129 match_pthrottling = &(match_pr->throttling);
130 match_pdomain = &(match_pthrottling->domain_info);
131 if (match_pdomain->domain != pdomain->domain)
132 continue;
133
134 /* Here i and j are in the same domain.
135 * If two TSD packages have the same domain, they
136 * should have the same num_porcessors and
137 * coordination type. Otherwise it will be regarded
138 * as illegal.
139 */
140 if (match_pdomain->num_processors != count_target) {
141 retval = -EINVAL;
142 goto err_ret;
143 }
144
145 if (pdomain->coord_type != match_pdomain->coord_type) {
146 retval = -EINVAL;
147 goto err_ret;
148 }
149
150 cpumask_set_cpu(j, covered_cpus);
151 cpumask_set_cpu(j, pthrottling->shared_cpu_map);
152 count++;
153 }
154 for_each_possible_cpu(j) {
155 if (i == j)
156 continue;
157
158 match_pr = per_cpu(processors, j);
159 if (!match_pr)
160 continue;
161
162 match_pthrottling = &(match_pr->throttling);
163 match_pdomain = &(match_pthrottling->domain_info);
164 if (match_pdomain->domain != pdomain->domain)
165 continue;
166
167 /*
168 * If some CPUS have the same domain, they
169 * will have the same shared_cpu_map.
170 */
171 cpumask_copy(match_pthrottling->shared_cpu_map,
172 pthrottling->shared_cpu_map);
173 }
174 }
175
176 err_ret:
177 free_cpumask_var(covered_cpus);
178
179 for_each_possible_cpu(i) {
180 pr = per_cpu(processors, i);
181 if (!pr)
182 continue;
183
184 /*
185 * Assume no coordination on any error parsing domain info.
186 * The coordination type will be forced as SW_ALL.
187 */
188 if (retval) {
189 pthrottling = &(pr->throttling);
190 cpumask_clear(pthrottling->shared_cpu_map);
191 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
192 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
193 }
194 }
195
196 return retval;
197 }
198
199 /*
200 * Update the T-state coordination after the _TSD
201 * data for all cpus is obtained.
202 */
203 void acpi_processor_throttling_init(void)
204 {
205 if (acpi_processor_update_tsd_coord())
206 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
207 "Assume no T-state coordination\n"));
208
209 return;
210 }
211
212 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
213 {
214 struct throttling_tstate *p_tstate = data;
215 struct acpi_processor *pr;
216 unsigned int cpu ;
217 int target_state;
218 struct acpi_processor_limit *p_limit;
219 struct acpi_processor_throttling *p_throttling;
220
221 cpu = p_tstate->cpu;
222 pr = per_cpu(processors, cpu);
223 if (!pr) {
224 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
225 return 0;
226 }
227 if (!pr->flags.throttling) {
228 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
229 "unsupported on CPU %d\n", cpu));
230 return 0;
231 }
232 target_state = p_tstate->target_state;
233 p_throttling = &(pr->throttling);
234 switch (event) {
235 case THROTTLING_PRECHANGE:
236 /*
237 * Prechange event is used to choose one proper t-state,
238 * which meets the limits of thermal, user and _TPC.
239 */
240 p_limit = &pr->limit;
241 if (p_limit->thermal.tx > target_state)
242 target_state = p_limit->thermal.tx;
243 if (p_limit->user.tx > target_state)
244 target_state = p_limit->user.tx;
245 if (pr->throttling_platform_limit > target_state)
246 target_state = pr->throttling_platform_limit;
247 if (target_state >= p_throttling->state_count) {
248 printk(KERN_WARNING
249 "Exceed the limit of T-state \n");
250 target_state = p_throttling->state_count - 1;
251 }
252 p_tstate->target_state = target_state;
253 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
254 "target T-state of CPU %d is T%d\n",
255 cpu, target_state));
256 break;
257 case THROTTLING_POSTCHANGE:
258 /*
259 * Postchange event is only used to update the
260 * T-state flag of acpi_processor_throttling.
261 */
262 p_throttling->state = target_state;
263 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
264 "CPU %d is switched to T%d\n",
265 cpu, target_state));
266 break;
267 default:
268 printk(KERN_WARNING
269 "Unsupported Throttling notifier event\n");
270 break;
271 }
272
273 return 0;
274 }
275
276 /*
277 * _TPC - Throttling Present Capabilities
278 */
279 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
280 {
281 acpi_status status = 0;
282 unsigned long long tpc = 0;
283
284 if (!pr)
285 return -EINVAL;
286 status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
287 if (ACPI_FAILURE(status)) {
288 if (status != AE_NOT_FOUND) {
289 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
290 }
291 return -ENODEV;
292 }
293 pr->throttling_platform_limit = (int)tpc;
294 return 0;
295 }
296
297 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
298 {
299 int result = 0;
300 int throttling_limit;
301 int current_state;
302 struct acpi_processor_limit *limit;
303 int target_state;
304
305 result = acpi_processor_get_platform_limit(pr);
306 if (result) {
307 /* Throttling Limit is unsupported */
308 return result;
309 }
310
311 throttling_limit = pr->throttling_platform_limit;
312 if (throttling_limit >= pr->throttling.state_count) {
313 /* Uncorrect Throttling Limit */
314 return -EINVAL;
315 }
316
317 current_state = pr->throttling.state;
318 if (current_state > throttling_limit) {
319 /*
320 * The current state can meet the requirement of
321 * _TPC limit. But it is reasonable that OSPM changes
322 * t-states from high to low for better performance.
323 * Of course the limit condition of thermal
324 * and user should be considered.
325 */
326 limit = &pr->limit;
327 target_state = throttling_limit;
328 if (limit->thermal.tx > target_state)
329 target_state = limit->thermal.tx;
330 if (limit->user.tx > target_state)
331 target_state = limit->user.tx;
332 } else if (current_state == throttling_limit) {
333 /*
334 * Unnecessary to change the throttling state
335 */
336 return 0;
337 } else {
338 /*
339 * If the current state is lower than the limit of _TPC, it
340 * will be forced to switch to the throttling state defined
341 * by throttling_platfor_limit.
342 * Because the previous state meets with the limit condition
343 * of thermal and user, it is unnecessary to check it again.
344 */
345 target_state = throttling_limit;
346 }
347 return acpi_processor_set_throttling(pr, target_state);
348 }
349
350 /*
351 * _PTC - Processor Throttling Control (and status) register location
352 */
353 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
354 {
355 int result = 0;
356 acpi_status status = 0;
357 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
358 union acpi_object *ptc = NULL;
359 union acpi_object obj = { 0 };
360 struct acpi_processor_throttling *throttling;
361
362 status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
363 if (ACPI_FAILURE(status)) {
364 if (status != AE_NOT_FOUND) {
365 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
366 }
367 return -ENODEV;
368 }
369
370 ptc = (union acpi_object *)buffer.pointer;
371 if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
372 || (ptc->package.count != 2)) {
373 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
374 result = -EFAULT;
375 goto end;
376 }
377
378 /*
379 * control_register
380 */
381
382 obj = ptc->package.elements[0];
383
384 if ((obj.type != ACPI_TYPE_BUFFER)
385 || (obj.buffer.length < sizeof(struct acpi_ptc_register))
386 || (obj.buffer.pointer == NULL)) {
387 printk(KERN_ERR PREFIX
388 "Invalid _PTC data (control_register)\n");
389 result = -EFAULT;
390 goto end;
391 }
392 memcpy(&pr->throttling.control_register, obj.buffer.pointer,
393 sizeof(struct acpi_ptc_register));
394
395 /*
396 * status_register
397 */
398
399 obj = ptc->package.elements[1];
400
401 if ((obj.type != ACPI_TYPE_BUFFER)
402 || (obj.buffer.length < sizeof(struct acpi_ptc_register))
403 || (obj.buffer.pointer == NULL)) {
404 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
405 result = -EFAULT;
406 goto end;
407 }
408
409 memcpy(&pr->throttling.status_register, obj.buffer.pointer,
410 sizeof(struct acpi_ptc_register));
411
412 throttling = &pr->throttling;
413
414 if ((throttling->control_register.bit_width +
415 throttling->control_register.bit_offset) > 32) {
416 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
417 result = -EFAULT;
418 goto end;
419 }
420
421 if ((throttling->status_register.bit_width +
422 throttling->status_register.bit_offset) > 32) {
423 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
424 result = -EFAULT;
425 goto end;
426 }
427
428 end:
429 kfree(buffer.pointer);
430
431 return result;
432 }
433
434 /*
435 * _TSS - Throttling Supported States
436 */
437 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
438 {
439 int result = 0;
440 acpi_status status = AE_OK;
441 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
442 struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
443 struct acpi_buffer state = { 0, NULL };
444 union acpi_object *tss = NULL;
445 int i;
446
447 status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
448 if (ACPI_FAILURE(status)) {
449 if (status != AE_NOT_FOUND) {
450 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
451 }
452 return -ENODEV;
453 }
454
455 tss = buffer.pointer;
456 if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
457 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
458 result = -EFAULT;
459 goto end;
460 }
461
462 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
463 tss->package.count));
464
465 pr->throttling.state_count = tss->package.count;
466 pr->throttling.states_tss =
467 kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
468 GFP_KERNEL);
469 if (!pr->throttling.states_tss) {
470 result = -ENOMEM;
471 goto end;
472 }
473
474 for (i = 0; i < pr->throttling.state_count; i++) {
475
476 struct acpi_processor_tx_tss *tx =
477 (struct acpi_processor_tx_tss *)&(pr->throttling.
478 states_tss[i]);
479
480 state.length = sizeof(struct acpi_processor_tx_tss);
481 state.pointer = tx;
482
483 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
484
485 status = acpi_extract_package(&(tss->package.elements[i]),
486 &format, &state);
487 if (ACPI_FAILURE(status)) {
488 ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
489 result = -EFAULT;
490 kfree(pr->throttling.states_tss);
491 goto end;
492 }
493
494 if (!tx->freqpercentage) {
495 printk(KERN_ERR PREFIX
496 "Invalid _TSS data: freq is zero\n");
497 result = -EFAULT;
498 kfree(pr->throttling.states_tss);
499 goto end;
500 }
501 }
502
503 end:
504 kfree(buffer.pointer);
505
506 return result;
507 }
508
509 /*
510 * _TSD - T-State Dependencies
511 */
512 static int acpi_processor_get_tsd(struct acpi_processor *pr)
513 {
514 int result = 0;
515 acpi_status status = AE_OK;
516 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
517 struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
518 struct acpi_buffer state = { 0, NULL };
519 union acpi_object *tsd = NULL;
520 struct acpi_tsd_package *pdomain;
521 struct acpi_processor_throttling *pthrottling;
522
523 pthrottling = &pr->throttling;
524 pthrottling->tsd_valid_flag = 0;
525
526 status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
527 if (ACPI_FAILURE(status)) {
528 if (status != AE_NOT_FOUND) {
529 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
530 }
531 return -ENODEV;
532 }
533
534 tsd = buffer.pointer;
535 if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
536 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
537 result = -EFAULT;
538 goto end;
539 }
540
541 if (tsd->package.count != 1) {
542 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
543 result = -EFAULT;
544 goto end;
545 }
546
547 pdomain = &(pr->throttling.domain_info);
548
549 state.length = sizeof(struct acpi_tsd_package);
550 state.pointer = pdomain;
551
552 status = acpi_extract_package(&(tsd->package.elements[0]),
553 &format, &state);
554 if (ACPI_FAILURE(status)) {
555 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
556 result = -EFAULT;
557 goto end;
558 }
559
560 if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
561 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
562 result = -EFAULT;
563 goto end;
564 }
565
566 if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
567 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
568 result = -EFAULT;
569 goto end;
570 }
571
572 pthrottling = &pr->throttling;
573 pthrottling->tsd_valid_flag = 1;
574 pthrottling->shared_type = pdomain->coord_type;
575 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
576 /*
577 * If the coordination type is not defined in ACPI spec,
578 * the tsd_valid_flag will be clear and coordination type
579 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
580 */
581 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
582 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
583 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
584 pthrottling->tsd_valid_flag = 0;
585 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
586 }
587
588 end:
589 kfree(buffer.pointer);
590 return result;
591 }
592
593 /* --------------------------------------------------------------------------
594 Throttling Control
595 -------------------------------------------------------------------------- */
596 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
597 {
598 int state = 0;
599 u32 value = 0;
600 u32 duty_mask = 0;
601 u32 duty_value = 0;
602
603 if (!pr)
604 return -EINVAL;
605
606 if (!pr->flags.throttling)
607 return -ENODEV;
608
609 pr->throttling.state = 0;
610
611 duty_mask = pr->throttling.state_count - 1;
612
613 duty_mask <<= pr->throttling.duty_offset;
614
615 local_irq_disable();
616
617 value = inl(pr->throttling.address);
618
619 /*
620 * Compute the current throttling state when throttling is enabled
621 * (bit 4 is on).
622 */
623 if (value & 0x10) {
624 duty_value = value & duty_mask;
625 duty_value >>= pr->throttling.duty_offset;
626
627 if (duty_value)
628 state = pr->throttling.state_count - duty_value;
629 }
630
631 pr->throttling.state = state;
632
633 local_irq_enable();
634
635 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
636 "Throttling state is T%d (%d%% throttling applied)\n",
637 state, pr->throttling.states[state].performance));
638
639 return 0;
640 }
641
642 #ifdef CONFIG_X86
643 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
644 acpi_integer * value)
645 {
646 struct cpuinfo_x86 *c;
647 u64 msr_high, msr_low;
648 unsigned int cpu;
649 u64 msr = 0;
650 int ret = -1;
651
652 cpu = pr->id;
653 c = &cpu_data(cpu);
654
655 if ((c->x86_vendor != X86_VENDOR_INTEL) ||
656 !cpu_has(c, X86_FEATURE_ACPI)) {
657 printk(KERN_ERR PREFIX
658 "HARDWARE addr space,NOT supported yet\n");
659 } else {
660 msr_low = 0;
661 msr_high = 0;
662 rdmsr_safe(MSR_IA32_THERM_CONTROL,
663 (u32 *)&msr_low , (u32 *) &msr_high);
664 msr = (msr_high << 32) | msr_low;
665 *value = (acpi_integer) msr;
666 ret = 0;
667 }
668 return ret;
669 }
670
671 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
672 {
673 struct cpuinfo_x86 *c;
674 unsigned int cpu;
675 int ret = -1;
676 u64 msr;
677
678 cpu = pr->id;
679 c = &cpu_data(cpu);
680
681 if ((c->x86_vendor != X86_VENDOR_INTEL) ||
682 !cpu_has(c, X86_FEATURE_ACPI)) {
683 printk(KERN_ERR PREFIX
684 "HARDWARE addr space,NOT supported yet\n");
685 } else {
686 msr = value;
687 wrmsr_safe(MSR_IA32_THERM_CONTROL,
688 msr & 0xffffffff, msr >> 32);
689 ret = 0;
690 }
691 return ret;
692 }
693 #else
694 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
695 acpi_integer * value)
696 {
697 printk(KERN_ERR PREFIX
698 "HARDWARE addr space,NOT supported yet\n");
699 return -1;
700 }
701
702 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
703 {
704 printk(KERN_ERR PREFIX
705 "HARDWARE addr space,NOT supported yet\n");
706 return -1;
707 }
708 #endif
709
710 static int acpi_read_throttling_status(struct acpi_processor *pr,
711 acpi_integer *value)
712 {
713 u32 bit_width, bit_offset;
714 u64 ptc_value;
715 u64 ptc_mask;
716 struct acpi_processor_throttling *throttling;
717 int ret = -1;
718
719 throttling = &pr->throttling;
720 switch (throttling->status_register.space_id) {
721 case ACPI_ADR_SPACE_SYSTEM_IO:
722 ptc_value = 0;
723 bit_width = throttling->status_register.bit_width;
724 bit_offset = throttling->status_register.bit_offset;
725
726 acpi_os_read_port((acpi_io_address) throttling->status_register.
727 address, (u32 *) &ptc_value,
728 (u32) (bit_width + bit_offset));
729 ptc_mask = (1 << bit_width) - 1;
730 *value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask);
731 ret = 0;
732 break;
733 case ACPI_ADR_SPACE_FIXED_HARDWARE:
734 ret = acpi_throttling_rdmsr(pr, value);
735 break;
736 default:
737 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
738 (u32) (throttling->status_register.space_id));
739 }
740 return ret;
741 }
742
743 static int acpi_write_throttling_state(struct acpi_processor *pr,
744 acpi_integer value)
745 {
746 u32 bit_width, bit_offset;
747 u64 ptc_value;
748 u64 ptc_mask;
749 struct acpi_processor_throttling *throttling;
750 int ret = -1;
751
752 throttling = &pr->throttling;
753 switch (throttling->control_register.space_id) {
754 case ACPI_ADR_SPACE_SYSTEM_IO:
755 bit_width = throttling->control_register.bit_width;
756 bit_offset = throttling->control_register.bit_offset;
757 ptc_mask = (1 << bit_width) - 1;
758 ptc_value = value & ptc_mask;
759
760 acpi_os_write_port((acpi_io_address) throttling->
761 control_register.address,
762 (u32) (ptc_value << bit_offset),
763 (u32) (bit_width + bit_offset));
764 ret = 0;
765 break;
766 case ACPI_ADR_SPACE_FIXED_HARDWARE:
767 ret = acpi_throttling_wrmsr(pr, value);
768 break;
769 default:
770 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
771 (u32) (throttling->control_register.space_id));
772 }
773 return ret;
774 }
775
776 static int acpi_get_throttling_state(struct acpi_processor *pr,
777 acpi_integer value)
778 {
779 int i;
780
781 for (i = 0; i < pr->throttling.state_count; i++) {
782 struct acpi_processor_tx_tss *tx =
783 (struct acpi_processor_tx_tss *)&(pr->throttling.
784 states_tss[i]);
785 if (tx->control == value)
786 break;
787 }
788 if (i > pr->throttling.state_count)
789 i = -1;
790 return i;
791 }
792
793 static int acpi_get_throttling_value(struct acpi_processor *pr,
794 int state, acpi_integer *value)
795 {
796 int ret = -1;
797
798 if (state >= 0 && state <= pr->throttling.state_count) {
799 struct acpi_processor_tx_tss *tx =
800 (struct acpi_processor_tx_tss *)&(pr->throttling.
801 states_tss[state]);
802 *value = tx->control;
803 ret = 0;
804 }
805 return ret;
806 }
807
808 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
809 {
810 int state = 0;
811 int ret;
812 acpi_integer value;
813
814 if (!pr)
815 return -EINVAL;
816
817 if (!pr->flags.throttling)
818 return -ENODEV;
819
820 pr->throttling.state = 0;
821
822 value = 0;
823 ret = acpi_read_throttling_status(pr, &value);
824 if (ret >= 0) {
825 state = acpi_get_throttling_state(pr, value);
826 pr->throttling.state = state;
827 }
828
829 return 0;
830 }
831
832 static int acpi_processor_get_throttling(struct acpi_processor *pr)
833 {
834 cpumask_var_t saved_mask;
835 int ret;
836
837 if (!pr)
838 return -EINVAL;
839
840 if (!pr->flags.throttling)
841 return -ENODEV;
842
843 if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
844 return -ENOMEM;
845
846 /*
847 * Migrate task to the cpu pointed by pr.
848 */
849 cpumask_copy(saved_mask, &current->cpus_allowed);
850 /* FIXME: use work_on_cpu() */
851 set_cpus_allowed_ptr(current, cpumask_of(pr->id));
852 ret = pr->throttling.acpi_processor_get_throttling(pr);
853 /* restore the previous state */
854 set_cpus_allowed_ptr(current, saved_mask);
855 free_cpumask_var(saved_mask);
856
857 return ret;
858 }
859
860 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
861 {
862 int i, step;
863
864 if (!pr->throttling.address) {
865 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
866 return -EINVAL;
867 } else if (!pr->throttling.duty_width) {
868 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
869 return -EINVAL;
870 }
871 /* TBD: Support duty_cycle values that span bit 4. */
872 else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
873 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
874 return -EINVAL;
875 }
876
877 pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
878
879 /*
880 * Compute state values. Note that throttling displays a linear power
881 * performance relationship (at 50% performance the CPU will consume
882 * 50% power). Values are in 1/10th of a percent to preserve accuracy.
883 */
884
885 step = (1000 / pr->throttling.state_count);
886
887 for (i = 0; i < pr->throttling.state_count; i++) {
888 pr->throttling.states[i].performance = 1000 - step * i;
889 pr->throttling.states[i].power = 1000 - step * i;
890 }
891 return 0;
892 }
893
894 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
895 int state)
896 {
897 u32 value = 0;
898 u32 duty_mask = 0;
899 u32 duty_value = 0;
900
901 if (!pr)
902 return -EINVAL;
903
904 if ((state < 0) || (state > (pr->throttling.state_count - 1)))
905 return -EINVAL;
906
907 if (!pr->flags.throttling)
908 return -ENODEV;
909
910 if (state == pr->throttling.state)
911 return 0;
912
913 if (state < pr->throttling_platform_limit)
914 return -EPERM;
915 /*
916 * Calculate the duty_value and duty_mask.
917 */
918 if (state) {
919 duty_value = pr->throttling.state_count - state;
920
921 duty_value <<= pr->throttling.duty_offset;
922
923 /* Used to clear all duty_value bits */
924 duty_mask = pr->throttling.state_count - 1;
925
926 duty_mask <<= acpi_gbl_FADT.duty_offset;
927 duty_mask = ~duty_mask;
928 }
929
930 local_irq_disable();
931
932 /*
933 * Disable throttling by writing a 0 to bit 4. Note that we must
934 * turn it off before you can change the duty_value.
935 */
936 value = inl(pr->throttling.address);
937 if (value & 0x10) {
938 value &= 0xFFFFFFEF;
939 outl(value, pr->throttling.address);
940 }
941
942 /*
943 * Write the new duty_value and then enable throttling. Note
944 * that a state value of 0 leaves throttling disabled.
945 */
946 if (state) {
947 value &= duty_mask;
948 value |= duty_value;
949 outl(value, pr->throttling.address);
950
951 value |= 0x00000010;
952 outl(value, pr->throttling.address);
953 }
954
955 pr->throttling.state = state;
956
957 local_irq_enable();
958
959 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
960 "Throttling state set to T%d (%d%%)\n", state,
961 (pr->throttling.states[state].performance ? pr->
962 throttling.states[state].performance / 10 : 0)));
963
964 return 0;
965 }
966
967 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
968 int state)
969 {
970 int ret;
971 acpi_integer value;
972
973 if (!pr)
974 return -EINVAL;
975
976 if ((state < 0) || (state > (pr->throttling.state_count - 1)))
977 return -EINVAL;
978
979 if (!pr->flags.throttling)
980 return -ENODEV;
981
982 if (state == pr->throttling.state)
983 return 0;
984
985 if (state < pr->throttling_platform_limit)
986 return -EPERM;
987
988 value = 0;
989 ret = acpi_get_throttling_value(pr, state, &value);
990 if (ret >= 0) {
991 acpi_write_throttling_state(pr, value);
992 pr->throttling.state = state;
993 }
994
995 return 0;
996 }
997
998 int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
999 {
1000 cpumask_var_t saved_mask;
1001 int ret = 0;
1002 unsigned int i;
1003 struct acpi_processor *match_pr;
1004 struct acpi_processor_throttling *p_throttling;
1005 struct throttling_tstate t_state;
1006 cpumask_var_t online_throttling_cpus;
1007
1008 if (!pr)
1009 return -EINVAL;
1010
1011 if (!pr->flags.throttling)
1012 return -ENODEV;
1013
1014 if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1015 return -EINVAL;
1016
1017 if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1018 return -ENOMEM;
1019
1020 if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1021 free_cpumask_var(saved_mask);
1022 return -ENOMEM;
1023 }
1024
1025 cpumask_copy(saved_mask, &current->cpus_allowed);
1026 t_state.target_state = state;
1027 p_throttling = &(pr->throttling);
1028 cpumask_and(online_throttling_cpus, cpu_online_mask,
1029 p_throttling->shared_cpu_map);
1030 /*
1031 * The throttling notifier will be called for every
1032 * affected cpu in order to get one proper T-state.
1033 * The notifier event is THROTTLING_PRECHANGE.
1034 */
1035 for_each_cpu(i, online_throttling_cpus) {
1036 t_state.cpu = i;
1037 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1038 &t_state);
1039 }
1040 /*
1041 * The function of acpi_processor_set_throttling will be called
1042 * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1043 * it is necessary to call it for every affected cpu. Otherwise
1044 * it can be called only for the cpu pointed by pr.
1045 */
1046 if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1047 /* FIXME: use work_on_cpu() */
1048 set_cpus_allowed_ptr(current, cpumask_of(pr->id));
1049 ret = p_throttling->acpi_processor_set_throttling(pr,
1050 t_state.target_state);
1051 } else {
1052 /*
1053 * When the T-state coordination is SW_ALL or HW_ALL,
1054 * it is necessary to set T-state for every affected
1055 * cpus.
1056 */
1057 for_each_cpu(i, online_throttling_cpus) {
1058 match_pr = per_cpu(processors, i);
1059 /*
1060 * If the pointer is invalid, we will report the
1061 * error message and continue.
1062 */
1063 if (!match_pr) {
1064 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1065 "Invalid Pointer for CPU %d\n", i));
1066 continue;
1067 }
1068 /*
1069 * If the throttling control is unsupported on CPU i,
1070 * we will report the error message and continue.
1071 */
1072 if (!match_pr->flags.throttling) {
1073 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1074 "Throttling Controll is unsupported "
1075 "on CPU %d\n", i));
1076 continue;
1077 }
1078 t_state.cpu = i;
1079 /* FIXME: use work_on_cpu() */
1080 set_cpus_allowed_ptr(current, cpumask_of(i));
1081 ret = match_pr->throttling.
1082 acpi_processor_set_throttling(
1083 match_pr, t_state.target_state);
1084 }
1085 }
1086 /*
1087 * After the set_throttling is called, the
1088 * throttling notifier is called for every
1089 * affected cpu to update the T-states.
1090 * The notifier event is THROTTLING_POSTCHANGE
1091 */
1092 for_each_cpu(i, online_throttling_cpus) {
1093 t_state.cpu = i;
1094 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1095 &t_state);
1096 }
1097 /* restore the previous state */
1098 /* FIXME: use work_on_cpu() */
1099 set_cpus_allowed_ptr(current, saved_mask);
1100 free_cpumask_var(online_throttling_cpus);
1101 free_cpumask_var(saved_mask);
1102 return ret;
1103 }
1104
1105 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1106 {
1107 int result = 0;
1108 struct acpi_processor_throttling *pthrottling;
1109
1110 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1111 "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1112 pr->throttling.address,
1113 pr->throttling.duty_offset,
1114 pr->throttling.duty_width));
1115
1116 if (!pr)
1117 return -EINVAL;
1118
1119 /*
1120 * Evaluate _PTC, _TSS and _TPC
1121 * They must all be present or none of them can be used.
1122 */
1123 if (acpi_processor_get_throttling_control(pr) ||
1124 acpi_processor_get_throttling_states(pr) ||
1125 acpi_processor_get_platform_limit(pr))
1126 {
1127 pr->throttling.acpi_processor_get_throttling =
1128 &acpi_processor_get_throttling_fadt;
1129 pr->throttling.acpi_processor_set_throttling =
1130 &acpi_processor_set_throttling_fadt;
1131 if (acpi_processor_get_fadt_info(pr))
1132 return 0;
1133 } else {
1134 pr->throttling.acpi_processor_get_throttling =
1135 &acpi_processor_get_throttling_ptc;
1136 pr->throttling.acpi_processor_set_throttling =
1137 &acpi_processor_set_throttling_ptc;
1138 }
1139
1140 /*
1141 * If TSD package for one CPU can't be parsed successfully, it means
1142 * that this CPU will have no coordination with other CPUs.
1143 */
1144 if (acpi_processor_get_tsd(pr)) {
1145 pthrottling = &pr->throttling;
1146 pthrottling->tsd_valid_flag = 0;
1147 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1148 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1149 }
1150
1151 /*
1152 * PIIX4 Errata: We don't support throttling on the original PIIX4.
1153 * This shouldn't be an issue as few (if any) mobile systems ever
1154 * used this part.
1155 */
1156 if (errata.piix4.throttle) {
1157 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1158 "Throttling not supported on PIIX4 A- or B-step\n"));
1159 return 0;
1160 }
1161
1162 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1163 pr->throttling.state_count));
1164
1165 pr->flags.throttling = 1;
1166
1167 /*
1168 * Disable throttling (if enabled). We'll let subsequent policy (e.g.
1169 * thermal) decide to lower performance if it so chooses, but for now
1170 * we'll crank up the speed.
1171 */
1172
1173 result = acpi_processor_get_throttling(pr);
1174 if (result)
1175 goto end;
1176
1177 if (pr->throttling.state) {
1178 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1179 "Disabling throttling (was T%d)\n",
1180 pr->throttling.state));
1181 result = acpi_processor_set_throttling(pr, 0);
1182 if (result)
1183 goto end;
1184 }
1185
1186 end:
1187 if (result)
1188 pr->flags.throttling = 0;
1189
1190 return result;
1191 }
1192
1193 /* proc interface */
1194
1195 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1196 void *offset)
1197 {
1198 struct acpi_processor *pr = seq->private;
1199 int i = 0;
1200 int result = 0;
1201
1202 if (!pr)
1203 goto end;
1204
1205 if (!(pr->throttling.state_count > 0)) {
1206 seq_puts(seq, "<not supported>\n");
1207 goto end;
1208 }
1209
1210 result = acpi_processor_get_throttling(pr);
1211
1212 if (result) {
1213 seq_puts(seq,
1214 "Could not determine current throttling state.\n");
1215 goto end;
1216 }
1217
1218 seq_printf(seq, "state count: %d\n"
1219 "active state: T%d\n"
1220 "state available: T%d to T%d\n",
1221 pr->throttling.state_count, pr->throttling.state,
1222 pr->throttling_platform_limit,
1223 pr->throttling.state_count - 1);
1224
1225 seq_puts(seq, "states:\n");
1226 if (pr->throttling.acpi_processor_get_throttling ==
1227 acpi_processor_get_throttling_fadt) {
1228 for (i = 0; i < pr->throttling.state_count; i++)
1229 seq_printf(seq, " %cT%d: %02d%%\n",
1230 (i == pr->throttling.state ? '*' : ' '), i,
1231 (pr->throttling.states[i].performance ? pr->
1232 throttling.states[i].performance / 10 : 0));
1233 } else {
1234 for (i = 0; i < pr->throttling.state_count; i++)
1235 seq_printf(seq, " %cT%d: %02d%%\n",
1236 (i == pr->throttling.state ? '*' : ' '), i,
1237 (int)pr->throttling.states_tss[i].
1238 freqpercentage);
1239 }
1240
1241 end:
1242 return 0;
1243 }
1244
1245 static int acpi_processor_throttling_open_fs(struct inode *inode,
1246 struct file *file)
1247 {
1248 return single_open(file, acpi_processor_throttling_seq_show,
1249 PDE(inode)->data);
1250 }
1251
1252 static ssize_t acpi_processor_write_throttling(struct file *file,
1253 const char __user * buffer,
1254 size_t count, loff_t * data)
1255 {
1256 int result = 0;
1257 struct seq_file *m = file->private_data;
1258 struct acpi_processor *pr = m->private;
1259 char state_string[5] = "";
1260 char *charp = NULL;
1261 size_t state_val = 0;
1262 char tmpbuf[5] = "";
1263
1264 if (!pr || (count > sizeof(state_string) - 1))
1265 return -EINVAL;
1266
1267 if (copy_from_user(state_string, buffer, count))
1268 return -EFAULT;
1269
1270 state_string[count] = '\0';
1271 if ((count > 0) && (state_string[count-1] == '\n'))
1272 state_string[count-1] = '\0';
1273
1274 charp = state_string;
1275 if ((state_string[0] == 't') || (state_string[0] == 'T'))
1276 charp++;
1277
1278 state_val = simple_strtoul(charp, NULL, 0);
1279 if (state_val >= pr->throttling.state_count)
1280 return -EINVAL;
1281
1282 snprintf(tmpbuf, 5, "%zu", state_val);
1283
1284 if (strcmp(tmpbuf, charp) != 0)
1285 return -EINVAL;
1286
1287 result = acpi_processor_set_throttling(pr, state_val);
1288 if (result)
1289 return result;
1290
1291 return count;
1292 }
1293
1294 struct file_operations acpi_processor_throttling_fops = {
1295 .owner = THIS_MODULE,
1296 .open = acpi_processor_throttling_open_fs,
1297 .read = seq_read,
1298 .write = acpi_processor_write_throttling,
1299 .llseek = seq_lseek,
1300 .release = single_release,
1301 };
Nao low-level kernelspace/userspace library that runs on our robots, Nao-Team HTWK