Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / processor_throttling.c
1 /*
2  * processor_throttling.c - Throttling submodule of the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *                      - Added processor hotplug support
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or (at
15  *  your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful, but
18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20  *  General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License along
23  *  with this program; if not, write to the Free Software Foundation, Inc.,
24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25  *
26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27  */
28
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/slab.h>
32 #include <linux/init.h>
33 #include <linux/sched.h>
34 #include <linux/cpufreq.h>
35
36 #include <asm/io.h>
37 #include <asm/uaccess.h>
38
39 #include <acpi/acpi_bus.h>
40 #include <acpi/acpi_drivers.h>
41 #include <acpi/processor.h>
42
43 #define PREFIX "ACPI: "
44
45 #define ACPI_PROCESSOR_CLASS            "processor"
46 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
47 ACPI_MODULE_NAME("processor_throttling");
48
49 /* ignore_tpc:
50  *  0 -> acpi processor driver doesn't ignore _TPC values
51  *  1 -> acpi processor driver ignores _TPC values
52  */
53 static int ignore_tpc;
54 module_param(ignore_tpc, int, 0644);
55 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
56
57 struct throttling_tstate {
58         unsigned int cpu;               /* cpu nr */
59         int target_state;               /* target T-state */
60 };
61
62 #define THROTTLING_PRECHANGE       (1)
63 #define THROTTLING_POSTCHANGE      (2)
64
65 static int acpi_processor_get_throttling(struct acpi_processor *pr);
66 int acpi_processor_set_throttling(struct acpi_processor *pr,
67                                                 int state, bool force);
68
69 static int acpi_processor_update_tsd_coord(void)
70 {
71         int count, count_target;
72         int retval = 0;
73         unsigned int i, j;
74         cpumask_var_t covered_cpus;
75         struct acpi_processor *pr, *match_pr;
76         struct acpi_tsd_package *pdomain, *match_pdomain;
77         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
78
79         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
80                 return -ENOMEM;
81
82         /*
83          * Now that we have _TSD data from all CPUs, lets setup T-state
84          * coordination between all CPUs.
85          */
86         for_each_possible_cpu(i) {
87                 pr = per_cpu(processors, i);
88                 if (!pr)
89                         continue;
90
91                 /* Basic validity check for domain info */
92                 pthrottling = &(pr->throttling);
93
94                 /*
95                  * If tsd package for one cpu is invalid, the coordination
96                  * among all CPUs is thought as invalid.
97                  * Maybe it is ugly.
98                  */
99                 if (!pthrottling->tsd_valid_flag) {
100                         retval = -EINVAL;
101                         break;
102                 }
103         }
104         if (retval)
105                 goto err_ret;
106
107         for_each_possible_cpu(i) {
108                 pr = per_cpu(processors, i);
109                 if (!pr)
110                         continue;
111
112                 if (cpumask_test_cpu(i, covered_cpus))
113                         continue;
114                 pthrottling = &pr->throttling;
115
116                 pdomain = &(pthrottling->domain_info);
117                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
118                 cpumask_set_cpu(i, covered_cpus);
119                 /*
120                  * If the number of processor in the TSD domain is 1, it is
121                  * unnecessary to parse the coordination for this CPU.
122                  */
123                 if (pdomain->num_processors <= 1)
124                         continue;
125
126                 /* Validate the Domain info */
127                 count_target = pdomain->num_processors;
128                 count = 1;
129
130                 for_each_possible_cpu(j) {
131                         if (i == j)
132                                 continue;
133
134                         match_pr = per_cpu(processors, j);
135                         if (!match_pr)
136                                 continue;
137
138                         match_pthrottling = &(match_pr->throttling);
139                         match_pdomain = &(match_pthrottling->domain_info);
140                         if (match_pdomain->domain != pdomain->domain)
141                                 continue;
142
143                         /* Here i and j are in the same domain.
144                          * If two TSD packages have the same domain, they
145                          * should have the same num_porcessors and
146                          * coordination type. Otherwise it will be regarded
147                          * as illegal.
148                          */
149                         if (match_pdomain->num_processors != count_target) {
150                                 retval = -EINVAL;
151                                 goto err_ret;
152                         }
153
154                         if (pdomain->coord_type != match_pdomain->coord_type) {
155                                 retval = -EINVAL;
156                                 goto err_ret;
157                         }
158
159                         cpumask_set_cpu(j, covered_cpus);
160                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
161                         count++;
162                 }
163                 for_each_possible_cpu(j) {
164                         if (i == j)
165                                 continue;
166
167                         match_pr = per_cpu(processors, j);
168                         if (!match_pr)
169                                 continue;
170
171                         match_pthrottling = &(match_pr->throttling);
172                         match_pdomain = &(match_pthrottling->domain_info);
173                         if (match_pdomain->domain != pdomain->domain)
174                                 continue;
175
176                         /*
177                          * If some CPUS have the same domain, they
178                          * will have the same shared_cpu_map.
179                          */
180                         cpumask_copy(match_pthrottling->shared_cpu_map,
181                                      pthrottling->shared_cpu_map);
182                 }
183         }
184
185 err_ret:
186         free_cpumask_var(covered_cpus);
187
188         for_each_possible_cpu(i) {
189                 pr = per_cpu(processors, i);
190                 if (!pr)
191                         continue;
192
193                 /*
194                  * Assume no coordination on any error parsing domain info.
195                  * The coordination type will be forced as SW_ALL.
196                  */
197                 if (retval) {
198                         pthrottling = &(pr->throttling);
199                         cpumask_clear(pthrottling->shared_cpu_map);
200                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
201                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
202                 }
203         }
204
205         return retval;
206 }
207
208 /*
209  * Update the T-state coordination after the _TSD
210  * data for all cpus is obtained.
211  */
212 void acpi_processor_throttling_init(void)
213 {
214         if (acpi_processor_update_tsd_coord())
215                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
216                         "Assume no T-state coordination\n"));
217
218         return;
219 }
220
221 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
222 {
223         struct throttling_tstate *p_tstate = data;
224         struct acpi_processor *pr;
225         unsigned int cpu ;
226         int target_state;
227         struct acpi_processor_limit *p_limit;
228         struct acpi_processor_throttling *p_throttling;
229
230         cpu = p_tstate->cpu;
231         pr = per_cpu(processors, cpu);
232         if (!pr) {
233                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
234                 return 0;
235         }
236         if (!pr->flags.throttling) {
237                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
238                                 "unsupported on CPU %d\n", cpu));
239                 return 0;
240         }
241         target_state = p_tstate->target_state;
242         p_throttling = &(pr->throttling);
243         switch (event) {
244         case THROTTLING_PRECHANGE:
245                 /*
246                  * Prechange event is used to choose one proper t-state,
247                  * which meets the limits of thermal, user and _TPC.
248                  */
249                 p_limit = &pr->limit;
250                 if (p_limit->thermal.tx > target_state)
251                         target_state = p_limit->thermal.tx;
252                 if (p_limit->user.tx > target_state)
253                         target_state = p_limit->user.tx;
254                 if (pr->throttling_platform_limit > target_state)
255                         target_state = pr->throttling_platform_limit;
256                 if (target_state >= p_throttling->state_count) {
257                         printk(KERN_WARNING
258                                 "Exceed the limit of T-state \n");
259                         target_state = p_throttling->state_count - 1;
260                 }
261                 p_tstate->target_state = target_state;
262                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
263                                 "target T-state of CPU %d is T%d\n",
264                                 cpu, target_state));
265                 break;
266         case THROTTLING_POSTCHANGE:
267                 /*
268                  * Postchange event is only used to update the
269                  * T-state flag of acpi_processor_throttling.
270                  */
271                 p_throttling->state = target_state;
272                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
273                                 "CPU %d is switched to T%d\n",
274                                 cpu, target_state));
275                 break;
276         default:
277                 printk(KERN_WARNING
278                         "Unsupported Throttling notifier event\n");
279                 break;
280         }
281
282         return 0;
283 }
284
285 /*
286  * _TPC - Throttling Present Capabilities
287  */
288 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
289 {
290         acpi_status status = 0;
291         unsigned long long tpc = 0;
292
293         if (!pr)
294                 return -EINVAL;
295
296         if (ignore_tpc)
297                 goto end;
298
299         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
300         if (ACPI_FAILURE(status)) {
301                 if (status != AE_NOT_FOUND) {
302                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
303                 }
304                 return -ENODEV;
305         }
306
307 end:
308         pr->throttling_platform_limit = (int)tpc;
309         return 0;
310 }
311
312 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
313 {
314         int result = 0;
315         int throttling_limit;
316         int current_state;
317         struct acpi_processor_limit *limit;
318         int target_state;
319
320         if (ignore_tpc)
321                 return 0;
322
323         result = acpi_processor_get_platform_limit(pr);
324         if (result) {
325                 /* Throttling Limit is unsupported */
326                 return result;
327         }
328
329         throttling_limit = pr->throttling_platform_limit;
330         if (throttling_limit >= pr->throttling.state_count) {
331                 /* Uncorrect Throttling Limit */
332                 return -EINVAL;
333         }
334
335         current_state = pr->throttling.state;
336         if (current_state > throttling_limit) {
337                 /*
338                  * The current state can meet the requirement of
339                  * _TPC limit. But it is reasonable that OSPM changes
340                  * t-states from high to low for better performance.
341                  * Of course the limit condition of thermal
342                  * and user should be considered.
343                  */
344                 limit = &pr->limit;
345                 target_state = throttling_limit;
346                 if (limit->thermal.tx > target_state)
347                         target_state = limit->thermal.tx;
348                 if (limit->user.tx > target_state)
349                         target_state = limit->user.tx;
350         } else if (current_state == throttling_limit) {
351                 /*
352                  * Unnecessary to change the throttling state
353                  */
354                 return 0;
355         } else {
356                 /*
357                  * If the current state is lower than the limit of _TPC, it
358                  * will be forced to switch to the throttling state defined
359                  * by throttling_platfor_limit.
360                  * Because the previous state meets with the limit condition
361                  * of thermal and user, it is unnecessary to check it again.
362                  */
363                 target_state = throttling_limit;
364         }
365         return acpi_processor_set_throttling(pr, target_state, false);
366 }
367
368 /*
369  * This function is used to reevaluate whether the T-state is valid
370  * after one CPU is onlined/offlined.
371  * It is noted that it won't reevaluate the following properties for
372  * the T-state.
373  *      1. Control method.
374  *      2. the number of supported T-state
375  *      3. TSD domain
376  */
377 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
378                                         unsigned long action)
379 {
380         int result = 0;
381
382         if (action == CPU_DEAD) {
383                 /* When one CPU is offline, the T-state throttling
384                  * will be invalidated.
385                  */
386                 pr->flags.throttling = 0;
387                 return;
388         }
389         /* the following is to recheck whether the T-state is valid for
390          * the online CPU
391          */
392         if (!pr->throttling.state_count) {
393                 /* If the number of T-state is invalid, it is
394                  * invalidated.
395                  */
396                 pr->flags.throttling = 0;
397                 return;
398         }
399         pr->flags.throttling = 1;
400
401         /* Disable throttling (if enabled).  We'll let subsequent
402          * policy (e.g.thermal) decide to lower performance if it
403          * so chooses, but for now we'll crank up the speed.
404          */
405
406         result = acpi_processor_get_throttling(pr);
407         if (result)
408                 goto end;
409
410         if (pr->throttling.state) {
411                 result = acpi_processor_set_throttling(pr, 0, false);
412                 if (result)
413                         goto end;
414         }
415
416 end:
417         if (result)
418                 pr->flags.throttling = 0;
419 }
420 /*
421  * _PTC - Processor Throttling Control (and status) register location
422  */
423 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
424 {
425         int result = 0;
426         acpi_status status = 0;
427         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
428         union acpi_object *ptc = NULL;
429         union acpi_object obj = { 0 };
430         struct acpi_processor_throttling *throttling;
431
432         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
433         if (ACPI_FAILURE(status)) {
434                 if (status != AE_NOT_FOUND) {
435                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
436                 }
437                 return -ENODEV;
438         }
439
440         ptc = (union acpi_object *)buffer.pointer;
441         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
442             || (ptc->package.count != 2)) {
443                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
444                 result = -EFAULT;
445                 goto end;
446         }
447
448         /*
449          * control_register
450          */
451
452         obj = ptc->package.elements[0];
453
454         if ((obj.type != ACPI_TYPE_BUFFER)
455             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
456             || (obj.buffer.pointer == NULL)) {
457                 printk(KERN_ERR PREFIX
458                        "Invalid _PTC data (control_register)\n");
459                 result = -EFAULT;
460                 goto end;
461         }
462         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
463                sizeof(struct acpi_ptc_register));
464
465         /*
466          * status_register
467          */
468
469         obj = ptc->package.elements[1];
470
471         if ((obj.type != ACPI_TYPE_BUFFER)
472             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
473             || (obj.buffer.pointer == NULL)) {
474                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
475                 result = -EFAULT;
476                 goto end;
477         }
478
479         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
480                sizeof(struct acpi_ptc_register));
481
482         throttling = &pr->throttling;
483
484         if ((throttling->control_register.bit_width +
485                 throttling->control_register.bit_offset) > 32) {
486                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
487                 result = -EFAULT;
488                 goto end;
489         }
490
491         if ((throttling->status_register.bit_width +
492                 throttling->status_register.bit_offset) > 32) {
493                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
494                 result = -EFAULT;
495                 goto end;
496         }
497
498       end:
499         kfree(buffer.pointer);
500
501         return result;
502 }
503
504 /*
505  * _TSS - Throttling Supported States
506  */
507 static int acpi_processor_get_throttling_states(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 *tss = NULL;
515         int i;
516
517         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
518         if (ACPI_FAILURE(status)) {
519                 if (status != AE_NOT_FOUND) {
520                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
521                 }
522                 return -ENODEV;
523         }
524
525         tss = buffer.pointer;
526         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
527                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
528                 result = -EFAULT;
529                 goto end;
530         }
531
532         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
533                           tss->package.count));
534
535         pr->throttling.state_count = tss->package.count;
536         pr->throttling.states_tss =
537             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
538                     GFP_KERNEL);
539         if (!pr->throttling.states_tss) {
540                 result = -ENOMEM;
541                 goto end;
542         }
543
544         for (i = 0; i < pr->throttling.state_count; i++) {
545
546                 struct acpi_processor_tx_tss *tx =
547                     (struct acpi_processor_tx_tss *)&(pr->throttling.
548                                                       states_tss[i]);
549
550                 state.length = sizeof(struct acpi_processor_tx_tss);
551                 state.pointer = tx;
552
553                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
554
555                 status = acpi_extract_package(&(tss->package.elements[i]),
556                                               &format, &state);
557                 if (ACPI_FAILURE(status)) {
558                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
559                         result = -EFAULT;
560                         kfree(pr->throttling.states_tss);
561                         goto end;
562                 }
563
564                 if (!tx->freqpercentage) {
565                         printk(KERN_ERR PREFIX
566                                "Invalid _TSS data: freq is zero\n");
567                         result = -EFAULT;
568                         kfree(pr->throttling.states_tss);
569                         goto end;
570                 }
571         }
572
573       end:
574         kfree(buffer.pointer);
575
576         return result;
577 }
578
579 /*
580  * _TSD - T-State Dependencies
581  */
582 static int acpi_processor_get_tsd(struct acpi_processor *pr)
583 {
584         int result = 0;
585         acpi_status status = AE_OK;
586         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
587         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
588         struct acpi_buffer state = { 0, NULL };
589         union acpi_object *tsd = NULL;
590         struct acpi_tsd_package *pdomain;
591         struct acpi_processor_throttling *pthrottling;
592
593         pthrottling = &pr->throttling;
594         pthrottling->tsd_valid_flag = 0;
595
596         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
597         if (ACPI_FAILURE(status)) {
598                 if (status != AE_NOT_FOUND) {
599                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
600                 }
601                 return -ENODEV;
602         }
603
604         tsd = buffer.pointer;
605         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
606                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
607                 result = -EFAULT;
608                 goto end;
609         }
610
611         if (tsd->package.count != 1) {
612                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
613                 result = -EFAULT;
614                 goto end;
615         }
616
617         pdomain = &(pr->throttling.domain_info);
618
619         state.length = sizeof(struct acpi_tsd_package);
620         state.pointer = pdomain;
621
622         status = acpi_extract_package(&(tsd->package.elements[0]),
623                                       &format, &state);
624         if (ACPI_FAILURE(status)) {
625                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
626                 result = -EFAULT;
627                 goto end;
628         }
629
630         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
631                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
632                 result = -EFAULT;
633                 goto end;
634         }
635
636         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
637                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
638                 result = -EFAULT;
639                 goto end;
640         }
641
642         pthrottling = &pr->throttling;
643         pthrottling->tsd_valid_flag = 1;
644         pthrottling->shared_type = pdomain->coord_type;
645         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
646         /*
647          * If the coordination type is not defined in ACPI spec,
648          * the tsd_valid_flag will be clear and coordination type
649          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
650          */
651         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
652                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
653                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
654                 pthrottling->tsd_valid_flag = 0;
655                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
656         }
657
658       end:
659         kfree(buffer.pointer);
660         return result;
661 }
662
663 /* --------------------------------------------------------------------------
664                               Throttling Control
665    -------------------------------------------------------------------------- */
666 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
667 {
668         int state = 0;
669         u32 value = 0;
670         u32 duty_mask = 0;
671         u32 duty_value = 0;
672
673         if (!pr)
674                 return -EINVAL;
675
676         if (!pr->flags.throttling)
677                 return -ENODEV;
678
679         pr->throttling.state = 0;
680
681         duty_mask = pr->throttling.state_count - 1;
682
683         duty_mask <<= pr->throttling.duty_offset;
684
685         local_irq_disable();
686
687         value = inl(pr->throttling.address);
688
689         /*
690          * Compute the current throttling state when throttling is enabled
691          * (bit 4 is on).
692          */
693         if (value & 0x10) {
694                 duty_value = value & duty_mask;
695                 duty_value >>= pr->throttling.duty_offset;
696
697                 if (duty_value)
698                         state = pr->throttling.state_count - duty_value;
699         }
700
701         pr->throttling.state = state;
702
703         local_irq_enable();
704
705         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
706                           "Throttling state is T%d (%d%% throttling applied)\n",
707                           state, pr->throttling.states[state].performance));
708
709         return 0;
710 }
711
712 #ifdef CONFIG_X86
713 static int acpi_throttling_rdmsr(u64 *value)
714 {
715         u64 msr_high, msr_low;
716         u64 msr = 0;
717         int ret = -1;
718
719         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
720                 !this_cpu_has(X86_FEATURE_ACPI)) {
721                 printk(KERN_ERR PREFIX
722                         "HARDWARE addr space,NOT supported yet\n");
723         } else {
724                 msr_low = 0;
725                 msr_high = 0;
726                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
727                         (u32 *)&msr_low , (u32 *) &msr_high);
728                 msr = (msr_high << 32) | msr_low;
729                 *value = (u64) msr;
730                 ret = 0;
731         }
732         return ret;
733 }
734
735 static int acpi_throttling_wrmsr(u64 value)
736 {
737         int ret = -1;
738         u64 msr;
739
740         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
741                 !this_cpu_has(X86_FEATURE_ACPI)) {
742                 printk(KERN_ERR PREFIX
743                         "HARDWARE addr space,NOT supported yet\n");
744         } else {
745                 msr = value;
746                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
747                         msr & 0xffffffff, msr >> 32);
748                 ret = 0;
749         }
750         return ret;
751 }
752 #else
753 static int acpi_throttling_rdmsr(u64 *value)
754 {
755         printk(KERN_ERR PREFIX
756                 "HARDWARE addr space,NOT supported yet\n");
757         return -1;
758 }
759
760 static int acpi_throttling_wrmsr(u64 value)
761 {
762         printk(KERN_ERR PREFIX
763                 "HARDWARE addr space,NOT supported yet\n");
764         return -1;
765 }
766 #endif
767
768 static int acpi_read_throttling_status(struct acpi_processor *pr,
769                                         u64 *value)
770 {
771         u32 bit_width, bit_offset;
772         u32 ptc_value;
773         u64 ptc_mask;
774         struct acpi_processor_throttling *throttling;
775         int ret = -1;
776
777         throttling = &pr->throttling;
778         switch (throttling->status_register.space_id) {
779         case ACPI_ADR_SPACE_SYSTEM_IO:
780                 bit_width = throttling->status_register.bit_width;
781                 bit_offset = throttling->status_register.bit_offset;
782
783                 acpi_os_read_port((acpi_io_address) throttling->status_register.
784                                   address, &ptc_value,
785                                   (u32) (bit_width + bit_offset));
786                 ptc_mask = (1 << bit_width) - 1;
787                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
788                 ret = 0;
789                 break;
790         case ACPI_ADR_SPACE_FIXED_HARDWARE:
791                 ret = acpi_throttling_rdmsr(value);
792                 break;
793         default:
794                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
795                        (u32) (throttling->status_register.space_id));
796         }
797         return ret;
798 }
799
800 static int acpi_write_throttling_state(struct acpi_processor *pr,
801                                 u64 value)
802 {
803         u32 bit_width, bit_offset;
804         u64 ptc_value;
805         u64 ptc_mask;
806         struct acpi_processor_throttling *throttling;
807         int ret = -1;
808
809         throttling = &pr->throttling;
810         switch (throttling->control_register.space_id) {
811         case ACPI_ADR_SPACE_SYSTEM_IO:
812                 bit_width = throttling->control_register.bit_width;
813                 bit_offset = throttling->control_register.bit_offset;
814                 ptc_mask = (1 << bit_width) - 1;
815                 ptc_value = value & ptc_mask;
816
817                 acpi_os_write_port((acpi_io_address) throttling->
818                                         control_register.address,
819                                         (u32) (ptc_value << bit_offset),
820                                         (u32) (bit_width + bit_offset));
821                 ret = 0;
822                 break;
823         case ACPI_ADR_SPACE_FIXED_HARDWARE:
824                 ret = acpi_throttling_wrmsr(value);
825                 break;
826         default:
827                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
828                        (u32) (throttling->control_register.space_id));
829         }
830         return ret;
831 }
832
833 static int acpi_get_throttling_state(struct acpi_processor *pr,
834                                 u64 value)
835 {
836         int i;
837
838         for (i = 0; i < pr->throttling.state_count; i++) {
839                 struct acpi_processor_tx_tss *tx =
840                     (struct acpi_processor_tx_tss *)&(pr->throttling.
841                                                       states_tss[i]);
842                 if (tx->control == value)
843                         return i;
844         }
845         return -1;
846 }
847
848 static int acpi_get_throttling_value(struct acpi_processor *pr,
849                         int state, u64 *value)
850 {
851         int ret = -1;
852
853         if (state >= 0 && state <= pr->throttling.state_count) {
854                 struct acpi_processor_tx_tss *tx =
855                     (struct acpi_processor_tx_tss *)&(pr->throttling.
856                                                       states_tss[state]);
857                 *value = tx->control;
858                 ret = 0;
859         }
860         return ret;
861 }
862
863 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
864 {
865         int state = 0;
866         int ret;
867         u64 value;
868
869         if (!pr)
870                 return -EINVAL;
871
872         if (!pr->flags.throttling)
873                 return -ENODEV;
874
875         pr->throttling.state = 0;
876
877         value = 0;
878         ret = acpi_read_throttling_status(pr, &value);
879         if (ret >= 0) {
880                 state = acpi_get_throttling_state(pr, value);
881                 if (state == -1) {
882                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
883                                 "Invalid throttling state, reset\n"));
884                         state = 0;
885                         ret = acpi_processor_set_throttling(pr, state, true);
886                         if (ret)
887                                 return ret;
888                 }
889                 pr->throttling.state = state;
890         }
891
892         return 0;
893 }
894
895 static int acpi_processor_get_throttling(struct acpi_processor *pr)
896 {
897         cpumask_var_t saved_mask;
898         int ret;
899
900         if (!pr)
901                 return -EINVAL;
902
903         if (!pr->flags.throttling)
904                 return -ENODEV;
905
906         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
907                 return -ENOMEM;
908
909         /*
910          * Migrate task to the cpu pointed by pr.
911          */
912         cpumask_copy(saved_mask, &current->cpus_allowed);
913         /* FIXME: use work_on_cpu() */
914         if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
915                 /* Can't migrate to the target pr->id CPU. Exit */
916                 free_cpumask_var(saved_mask);
917                 return -ENODEV;
918         }
919         ret = pr->throttling.acpi_processor_get_throttling(pr);
920         /* restore the previous state */
921         set_cpus_allowed_ptr(current, saved_mask);
922         free_cpumask_var(saved_mask);
923
924         return ret;
925 }
926
927 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
928 {
929         int i, step;
930
931         if (!pr->throttling.address) {
932                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
933                 return -EINVAL;
934         } else if (!pr->throttling.duty_width) {
935                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
936                 return -EINVAL;
937         }
938         /* TBD: Support duty_cycle values that span bit 4. */
939         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
940                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
941                 return -EINVAL;
942         }
943
944         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
945
946         /*
947          * Compute state values. Note that throttling displays a linear power
948          * performance relationship (at 50% performance the CPU will consume
949          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
950          */
951
952         step = (1000 / pr->throttling.state_count);
953
954         for (i = 0; i < pr->throttling.state_count; i++) {
955                 pr->throttling.states[i].performance = 1000 - step * i;
956                 pr->throttling.states[i].power = 1000 - step * i;
957         }
958         return 0;
959 }
960
961 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
962                                               int state, bool force)
963 {
964         u32 value = 0;
965         u32 duty_mask = 0;
966         u32 duty_value = 0;
967
968         if (!pr)
969                 return -EINVAL;
970
971         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
972                 return -EINVAL;
973
974         if (!pr->flags.throttling)
975                 return -ENODEV;
976
977         if (!force && (state == pr->throttling.state))
978                 return 0;
979
980         if (state < pr->throttling_platform_limit)
981                 return -EPERM;
982         /*
983          * Calculate the duty_value and duty_mask.
984          */
985         if (state) {
986                 duty_value = pr->throttling.state_count - state;
987
988                 duty_value <<= pr->throttling.duty_offset;
989
990                 /* Used to clear all duty_value bits */
991                 duty_mask = pr->throttling.state_count - 1;
992
993                 duty_mask <<= acpi_gbl_FADT.duty_offset;
994                 duty_mask = ~duty_mask;
995         }
996
997         local_irq_disable();
998
999         /*
1000          * Disable throttling by writing a 0 to bit 4.  Note that we must
1001          * turn it off before you can change the duty_value.
1002          */
1003         value = inl(pr->throttling.address);
1004         if (value & 0x10) {
1005                 value &= 0xFFFFFFEF;
1006                 outl(value, pr->throttling.address);
1007         }
1008
1009         /*
1010          * Write the new duty_value and then enable throttling.  Note
1011          * that a state value of 0 leaves throttling disabled.
1012          */
1013         if (state) {
1014                 value &= duty_mask;
1015                 value |= duty_value;
1016                 outl(value, pr->throttling.address);
1017
1018                 value |= 0x00000010;
1019                 outl(value, pr->throttling.address);
1020         }
1021
1022         pr->throttling.state = state;
1023
1024         local_irq_enable();
1025
1026         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1027                           "Throttling state set to T%d (%d%%)\n", state,
1028                           (pr->throttling.states[state].performance ? pr->
1029                            throttling.states[state].performance / 10 : 0)));
1030
1031         return 0;
1032 }
1033
1034 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1035                                              int state, bool force)
1036 {
1037         int ret;
1038         u64 value;
1039
1040         if (!pr)
1041                 return -EINVAL;
1042
1043         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1044                 return -EINVAL;
1045
1046         if (!pr->flags.throttling)
1047                 return -ENODEV;
1048
1049         if (!force && (state == pr->throttling.state))
1050                 return 0;
1051
1052         if (state < pr->throttling_platform_limit)
1053                 return -EPERM;
1054
1055         value = 0;
1056         ret = acpi_get_throttling_value(pr, state, &value);
1057         if (ret >= 0) {
1058                 acpi_write_throttling_state(pr, value);
1059                 pr->throttling.state = state;
1060         }
1061
1062         return 0;
1063 }
1064
1065 int acpi_processor_set_throttling(struct acpi_processor *pr,
1066                                                 int state, bool force)
1067 {
1068         cpumask_var_t saved_mask;
1069         int ret = 0;
1070         unsigned int i;
1071         struct acpi_processor *match_pr;
1072         struct acpi_processor_throttling *p_throttling;
1073         struct throttling_tstate t_state;
1074         cpumask_var_t online_throttling_cpus;
1075
1076         if (!pr)
1077                 return -EINVAL;
1078
1079         if (!pr->flags.throttling)
1080                 return -ENODEV;
1081
1082         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1083                 return -EINVAL;
1084
1085         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1086                 return -ENOMEM;
1087
1088         if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1089                 free_cpumask_var(saved_mask);
1090                 return -ENOMEM;
1091         }
1092
1093         if (cpu_is_offline(pr->id)) {
1094                 /*
1095                  * the cpu pointed by pr->id is offline. Unnecessary to change
1096                  * the throttling state any more.
1097                  */
1098                 return -ENODEV;
1099         }
1100
1101         cpumask_copy(saved_mask, &current->cpus_allowed);
1102         t_state.target_state = state;
1103         p_throttling = &(pr->throttling);
1104         cpumask_and(online_throttling_cpus, cpu_online_mask,
1105                     p_throttling->shared_cpu_map);
1106         /*
1107          * The throttling notifier will be called for every
1108          * affected cpu in order to get one proper T-state.
1109          * The notifier event is THROTTLING_PRECHANGE.
1110          */
1111         for_each_cpu(i, online_throttling_cpus) {
1112                 t_state.cpu = i;
1113                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1114                                                         &t_state);
1115         }
1116         /*
1117          * The function of acpi_processor_set_throttling will be called
1118          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1119          * it is necessary to call it for every affected cpu. Otherwise
1120          * it can be called only for the cpu pointed by pr.
1121          */
1122         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1123                 /* FIXME: use work_on_cpu() */
1124                 if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
1125                         /* Can't migrate to the pr->id CPU. Exit */
1126                         ret = -ENODEV;
1127                         goto exit;
1128                 }
1129                 ret = p_throttling->acpi_processor_set_throttling(pr,
1130                                                 t_state.target_state, force);
1131         } else {
1132                 /*
1133                  * When the T-state coordination is SW_ALL or HW_ALL,
1134                  * it is necessary to set T-state for every affected
1135                  * cpus.
1136                  */
1137                 for_each_cpu(i, online_throttling_cpus) {
1138                         match_pr = per_cpu(processors, i);
1139                         /*
1140                          * If the pointer is invalid, we will report the
1141                          * error message and continue.
1142                          */
1143                         if (!match_pr) {
1144                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1145                                         "Invalid Pointer for CPU %d\n", i));
1146                                 continue;
1147                         }
1148                         /*
1149                          * If the throttling control is unsupported on CPU i,
1150                          * we will report the error message and continue.
1151                          */
1152                         if (!match_pr->flags.throttling) {
1153                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1154                                         "Throttling Control is unsupported "
1155                                         "on CPU %d\n", i));
1156                                 continue;
1157                         }
1158                         t_state.cpu = i;
1159                         /* FIXME: use work_on_cpu() */
1160                         if (set_cpus_allowed_ptr(current, cpumask_of(i)))
1161                                 continue;
1162                         ret = match_pr->throttling.
1163                                 acpi_processor_set_throttling(
1164                                 match_pr, t_state.target_state, force);
1165                 }
1166         }
1167         /*
1168          * After the set_throttling is called, the
1169          * throttling notifier is called for every
1170          * affected cpu to update the T-states.
1171          * The notifier event is THROTTLING_POSTCHANGE
1172          */
1173         for_each_cpu(i, online_throttling_cpus) {
1174                 t_state.cpu = i;
1175                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1176                                                         &t_state);
1177         }
1178         /* restore the previous state */
1179         /* FIXME: use work_on_cpu() */
1180         set_cpus_allowed_ptr(current, saved_mask);
1181 exit:
1182         free_cpumask_var(online_throttling_cpus);
1183         free_cpumask_var(saved_mask);
1184         return ret;
1185 }
1186
1187 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1188 {
1189         int result = 0;
1190         struct acpi_processor_throttling *pthrottling;
1191
1192         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1193                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1194                           pr->throttling.address,
1195                           pr->throttling.duty_offset,
1196                           pr->throttling.duty_width));
1197
1198         /*
1199          * Evaluate _PTC, _TSS and _TPC
1200          * They must all be present or none of them can be used.
1201          */
1202         if (acpi_processor_get_throttling_control(pr) ||
1203                 acpi_processor_get_throttling_states(pr) ||
1204                 acpi_processor_get_platform_limit(pr))
1205         {
1206                 pr->throttling.acpi_processor_get_throttling =
1207                     &acpi_processor_get_throttling_fadt;
1208                 pr->throttling.acpi_processor_set_throttling =
1209                     &acpi_processor_set_throttling_fadt;
1210                 if (acpi_processor_get_fadt_info(pr))
1211                         return 0;
1212         } else {
1213                 pr->throttling.acpi_processor_get_throttling =
1214                     &acpi_processor_get_throttling_ptc;
1215                 pr->throttling.acpi_processor_set_throttling =
1216                     &acpi_processor_set_throttling_ptc;
1217         }
1218
1219         /*
1220          * If TSD package for one CPU can't be parsed successfully, it means
1221          * that this CPU will have no coordination with other CPUs.
1222          */
1223         if (acpi_processor_get_tsd(pr)) {
1224                 pthrottling = &pr->throttling;
1225                 pthrottling->tsd_valid_flag = 0;
1226                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1227                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1228         }
1229
1230         /*
1231          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1232          * This shouldn't be an issue as few (if any) mobile systems ever
1233          * used this part.
1234          */
1235         if (errata.piix4.throttle) {
1236                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1237                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1238                 return 0;
1239         }
1240
1241         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1242                           pr->throttling.state_count));
1243
1244         pr->flags.throttling = 1;
1245
1246         /*
1247          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1248          * thermal) decide to lower performance if it so chooses, but for now
1249          * we'll crank up the speed.
1250          */
1251
1252         result = acpi_processor_get_throttling(pr);
1253         if (result)
1254                 goto end;
1255
1256         if (pr->throttling.state) {
1257                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1258                                   "Disabling throttling (was T%d)\n",
1259                                   pr->throttling.state));
1260                 result = acpi_processor_set_throttling(pr, 0, false);
1261                 if (result)
1262                         goto end;
1263         }
1264
1265       end:
1266         if (result)
1267                 pr->flags.throttling = 0;
1268
1269         return result;
1270 }
1271