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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9 * - Added processor hotplug support
10 */
11
12#define pr_fmt(fmt) "ACPI: " fmt
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/cpufreq.h>
18#include <linux/slab.h>
19#include <linux/acpi.h>
20#include <acpi/processor.h>
21#ifdef CONFIG_X86
22#include <asm/cpufeature.h>
23#endif
24
25#define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
26
27/*
28 * _PPC support is implemented as a CPUfreq policy notifier:
29 * This means each time a CPUfreq driver registered also with
30 * the ACPI core is asked to change the speed policy, the maximum
31 * value is adjusted so that it is within the platform limit.
32 *
33 * Also, when a new platform limit value is detected, the CPUfreq
34 * policy is adjusted accordingly.
35 */
36
37/* ignore_ppc:
38 * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
39 * ignore _PPC
40 * 0 -> cpufreq low level drivers initialized -> consider _PPC values
41 * 1 -> ignore _PPC totally -> forced by user through boot param
42 */
43static int ignore_ppc = -1;
44module_param(ignore_ppc, int, 0644);
45MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
46 "limited by BIOS, this should help");
47
48static bool acpi_processor_ppc_in_use;
49
50static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
51{
52 acpi_status status = 0;
53 unsigned long long ppc = 0;
54 s32 qos_value;
55 int index;
56 int ret;
57
58 if (!pr)
59 return -EINVAL;
60
61 /*
62 * _PPC indicates the maximum state currently supported by the platform
63 * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
64 */
65 status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
66 if (status != AE_NOT_FOUND) {
67 acpi_processor_ppc_in_use = true;
68
69 if (ACPI_FAILURE(status)) {
70 acpi_evaluation_failure_warn(pr->handle, "_PPC", status);
71 return -ENODEV;
72 }
73 }
74
75 index = ppc;
76
77 if (pr->performance_platform_limit == index ||
78 ppc >= pr->performance->state_count)
79 return 0;
80
81 pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
82 index, index ? "is" : "is not");
83
84 pr->performance_platform_limit = index;
85
86 if (unlikely(!freq_qos_request_active(&pr->perflib_req)))
87 return 0;
88
89 /*
90 * If _PPC returns 0, it means that all of the available states can be
91 * used ("no limit").
92 */
93 if (index == 0)
94 qos_value = FREQ_QOS_MAX_DEFAULT_VALUE;
95 else
96 qos_value = pr->performance->states[index].core_frequency * 1000;
97
98 ret = freq_qos_update_request(&pr->perflib_req, qos_value);
99 if (ret < 0) {
100 pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n",
101 pr->id, ret);
102 }
103
104 return 0;
105}
106
107#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
108/*
109 * acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status
110 * @handle: ACPI processor handle
111 * @status: the status code of _PPC evaluation
112 * 0: success. OSPM is now using the performance state specified.
113 * 1: failure. OSPM has not changed the number of P-states in use
114 */
115static void acpi_processor_ppc_ost(acpi_handle handle, int status)
116{
117 if (acpi_has_method(handle, "_OST"))
118 acpi_evaluate_ost(handle, ACPI_PROCESSOR_NOTIFY_PERFORMANCE,
119 status, NULL);
120}
121
122void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
123{
124 int ret;
125
126 if (ignore_ppc || !pr->performance) {
127 /*
128 * Only when it is notification event, the _OST object
129 * will be evaluated. Otherwise it is skipped.
130 */
131 if (event_flag)
132 acpi_processor_ppc_ost(pr->handle, 1);
133 return;
134 }
135
136 ret = acpi_processor_get_platform_limit(pr);
137 /*
138 * Only when it is notification event, the _OST object
139 * will be evaluated. Otherwise it is skipped.
140 */
141 if (event_flag) {
142 if (ret < 0)
143 acpi_processor_ppc_ost(pr->handle, 1);
144 else
145 acpi_processor_ppc_ost(pr->handle, 0);
146 }
147 if (ret >= 0)
148 cpufreq_update_limits(pr->id);
149}
150
151int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
152{
153 struct acpi_processor *pr;
154
155 pr = per_cpu(processors, cpu);
156 if (!pr || !pr->performance || !pr->performance->state_count)
157 return -ENODEV;
158
159 *limit = pr->performance->states[pr->performance_platform_limit].
160 core_frequency * 1000;
161 return 0;
162}
163EXPORT_SYMBOL(acpi_processor_get_bios_limit);
164
165void acpi_processor_ignore_ppc_init(void)
166{
167 if (ignore_ppc < 0)
168 ignore_ppc = 0;
169}
170
171void acpi_processor_ppc_init(struct cpufreq_policy *policy)
172{
173 unsigned int cpu;
174
175 for_each_cpu(cpu, policy->related_cpus) {
176 struct acpi_processor *pr = per_cpu(processors, cpu);
177 int ret;
178
179 if (!pr)
180 continue;
181
182 /*
183 * Reset performance_platform_limit in case there is a stale
184 * value in it, so as to make it match the "no limit" QoS value
185 * below.
186 */
187 pr->performance_platform_limit = 0;
188
189 ret = freq_qos_add_request(&policy->constraints,
190 &pr->perflib_req, FREQ_QOS_MAX,
191 FREQ_QOS_MAX_DEFAULT_VALUE);
192 if (ret < 0)
193 pr_err("Failed to add freq constraint for CPU%d (%d)\n",
194 cpu, ret);
195 }
196}
197
198void acpi_processor_ppc_exit(struct cpufreq_policy *policy)
199{
200 unsigned int cpu;
201
202 for_each_cpu(cpu, policy->related_cpus) {
203 struct acpi_processor *pr = per_cpu(processors, cpu);
204
205 if (pr)
206 freq_qos_remove_request(&pr->perflib_req);
207 }
208}
209
210#ifdef CONFIG_X86
211
212static DEFINE_MUTEX(performance_mutex);
213
214static int acpi_processor_get_performance_control(struct acpi_processor *pr)
215{
216 int result = 0;
217 acpi_status status = 0;
218 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
219 union acpi_object *pct = NULL;
220 union acpi_object obj = { 0 };
221
222 status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
223 if (ACPI_FAILURE(status)) {
224 acpi_evaluation_failure_warn(pr->handle, "_PCT", status);
225 return -ENODEV;
226 }
227
228 pct = (union acpi_object *)buffer.pointer;
229 if (!pct || pct->type != ACPI_TYPE_PACKAGE || pct->package.count != 2) {
230 pr_err("Invalid _PCT data\n");
231 result = -EFAULT;
232 goto end;
233 }
234
235 /*
236 * control_register
237 */
238
239 obj = pct->package.elements[0];
240
241 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER ||
242 obj.buffer.length < sizeof(struct acpi_pct_register)) {
243 pr_err("Invalid _PCT data (control_register)\n");
244 result = -EFAULT;
245 goto end;
246 }
247 memcpy(&pr->performance->control_register, obj.buffer.pointer,
248 sizeof(struct acpi_pct_register));
249
250 /*
251 * status_register
252 */
253
254 obj = pct->package.elements[1];
255
256 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER ||
257 obj.buffer.length < sizeof(struct acpi_pct_register)) {
258 pr_err("Invalid _PCT data (status_register)\n");
259 result = -EFAULT;
260 goto end;
261 }
262
263 memcpy(&pr->performance->status_register, obj.buffer.pointer,
264 sizeof(struct acpi_pct_register));
265
266end:
267 kfree(buffer.pointer);
268
269 return result;
270}
271
272/*
273 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding
274 * in their ACPI data. Calculate the real values and fix up the _PSS data.
275 */
276static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
277{
278 u32 hi, lo, fid, did;
279 int index = px->control & 0x00000007;
280
281 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
282 return;
283
284 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) ||
285 boot_cpu_data.x86 == 0x11) {
286 rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
287 /*
288 * MSR C001_0064+:
289 * Bit 63: PstateEn. Read-write. If set, the P-state is valid.
290 */
291 if (!(hi & BIT(31)))
292 return;
293
294 fid = lo & 0x3f;
295 did = (lo >> 6) & 7;
296 if (boot_cpu_data.x86 == 0x10)
297 px->core_frequency = (100 * (fid + 0x10)) >> did;
298 else
299 px->core_frequency = (100 * (fid + 8)) >> did;
300 }
301}
302
303static int acpi_processor_get_performance_states(struct acpi_processor *pr)
304{
305 int result = 0;
306 acpi_status status = AE_OK;
307 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
308 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
309 struct acpi_buffer state = { 0, NULL };
310 union acpi_object *pss = NULL;
311 int i;
312 int last_invalid = -1;
313
314 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
315 if (ACPI_FAILURE(status)) {
316 acpi_evaluation_failure_warn(pr->handle, "_PSS", status);
317 return -ENODEV;
318 }
319
320 pss = buffer.pointer;
321 if (!pss || pss->type != ACPI_TYPE_PACKAGE) {
322 pr_err("Invalid _PSS data\n");
323 result = -EFAULT;
324 goto end;
325 }
326
327 acpi_handle_debug(pr->handle, "Found %d performance states\n",
328 pss->package.count);
329
330 pr->performance->state_count = pss->package.count;
331 pr->performance->states =
332 kmalloc_array(pss->package.count,
333 sizeof(struct acpi_processor_px),
334 GFP_KERNEL);
335 if (!pr->performance->states) {
336 result = -ENOMEM;
337 goto end;
338 }
339
340 for (i = 0; i < pr->performance->state_count; i++) {
341
342 struct acpi_processor_px *px = &(pr->performance->states[i]);
343
344 state.length = sizeof(struct acpi_processor_px);
345 state.pointer = px;
346
347 acpi_handle_debug(pr->handle, "Extracting state %d\n", i);
348
349 status = acpi_extract_package(&(pss->package.elements[i]),
350 &format, &state);
351 if (ACPI_FAILURE(status)) {
352 acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n",
353 acpi_format_exception(status));
354 result = -EFAULT;
355 kfree(pr->performance->states);
356 goto end;
357 }
358
359 amd_fixup_frequency(px, i);
360
361 acpi_handle_debug(pr->handle,
362 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
363 i,
364 (u32) px->core_frequency,
365 (u32) px->power,
366 (u32) px->transition_latency,
367 (u32) px->bus_master_latency,
368 (u32) px->control, (u32) px->status);
369
370 /*
371 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq
372 */
373 if (!px->core_frequency ||
374 (u32)(px->core_frequency * 1000) != px->core_frequency * 1000) {
375 pr_err(FW_BUG
376 "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n",
377 pr->id, px->core_frequency);
378 if (last_invalid == -1)
379 last_invalid = i;
380 } else {
381 if (last_invalid != -1) {
382 /*
383 * Copy this valid entry over last_invalid entry
384 */
385 memcpy(&(pr->performance->states[last_invalid]),
386 px, sizeof(struct acpi_processor_px));
387 ++last_invalid;
388 }
389 }
390 }
391
392 if (last_invalid == 0) {
393 pr_err(FW_BUG
394 "No valid BIOS _PSS frequency found for processor %d\n", pr->id);
395 result = -EFAULT;
396 kfree(pr->performance->states);
397 pr->performance->states = NULL;
398 }
399
400 if (last_invalid > 0)
401 pr->performance->state_count = last_invalid;
402
403end:
404 kfree(buffer.pointer);
405
406 return result;
407}
408
409int acpi_processor_get_performance_info(struct acpi_processor *pr)
410{
411 int result = 0;
412
413 if (!pr || !pr->performance || !pr->handle)
414 return -EINVAL;
415
416 if (!acpi_has_method(pr->handle, "_PCT")) {
417 acpi_handle_debug(pr->handle,
418 "ACPI-based processor performance control unavailable\n");
419 return -ENODEV;
420 }
421
422 result = acpi_processor_get_performance_control(pr);
423 if (result)
424 goto update_bios;
425
426 result = acpi_processor_get_performance_states(pr);
427 if (result)
428 goto update_bios;
429
430 /* We need to call _PPC once when cpufreq starts */
431 if (ignore_ppc != 1)
432 result = acpi_processor_get_platform_limit(pr);
433
434 return result;
435
436 /*
437 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
438 * the BIOS is older than the CPU and does not know its frequencies
439 */
440 update_bios:
441 if (acpi_has_method(pr->handle, "_PPC")) {
442 if(boot_cpu_has(X86_FEATURE_EST))
443 pr_warn(FW_BUG "BIOS needs update for CPU "
444 "frequency support\n");
445 }
446 return result;
447}
448EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info);
449
450int acpi_processor_pstate_control(void)
451{
452 acpi_status status;
453
454 if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control)
455 return 0;
456
457 pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n",
458 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command);
459
460 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
461 (u32)acpi_gbl_FADT.pstate_control, 8);
462 if (ACPI_SUCCESS(status))
463 return 1;
464
465 pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n",
466 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command,
467 acpi_format_exception(status));
468 return -EIO;
469}
470
471int acpi_processor_notify_smm(struct module *calling_module)
472{
473 static int is_done;
474 int result = 0;
475
476 if (!acpi_processor_cpufreq_init)
477 return -EBUSY;
478
479 if (!try_module_get(calling_module))
480 return -EINVAL;
481
482 /*
483 * is_done is set to negative if an error occurs and to 1 if no error
484 * occurrs, but SMM has been notified already. This avoids repeated
485 * notification which might lead to unexpected results.
486 */
487 if (is_done != 0) {
488 if (is_done < 0)
489 result = is_done;
490
491 goto out_put;
492 }
493
494 result = acpi_processor_pstate_control();
495 if (result <= 0) {
496 if (result) {
497 is_done = result;
498 } else {
499 pr_debug("No SMI port or pstate_control\n");
500 is_done = 1;
501 }
502 goto out_put;
503 }
504
505 is_done = 1;
506 /*
507 * Success. If there _PPC, unloading the cpufreq driver would be risky,
508 * so disallow it in that case.
509 */
510 if (acpi_processor_ppc_in_use)
511 return 0;
512
513out_put:
514 module_put(calling_module);
515 return result;
516}
517EXPORT_SYMBOL(acpi_processor_notify_smm);
518
519int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
520{
521 int result = 0;
522 acpi_status status = AE_OK;
523 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
524 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
525 struct acpi_buffer state = {0, NULL};
526 union acpi_object *psd = NULL;
527
528 status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer);
529 if (ACPI_FAILURE(status)) {
530 return -ENODEV;
531 }
532
533 psd = buffer.pointer;
534 if (!psd || psd->type != ACPI_TYPE_PACKAGE) {
535 pr_err("Invalid _PSD data\n");
536 result = -EFAULT;
537 goto end;
538 }
539
540 if (psd->package.count != 1) {
541 pr_err("Invalid _PSD data\n");
542 result = -EFAULT;
543 goto end;
544 }
545
546 state.length = sizeof(struct acpi_psd_package);
547 state.pointer = pdomain;
548
549 status = acpi_extract_package(&(psd->package.elements[0]), &format, &state);
550 if (ACPI_FAILURE(status)) {
551 pr_err("Invalid _PSD data\n");
552 result = -EFAULT;
553 goto end;
554 }
555
556 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
557 pr_err("Unknown _PSD:num_entries\n");
558 result = -EFAULT;
559 goto end;
560 }
561
562 if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
563 pr_err("Unknown _PSD:revision\n");
564 result = -EFAULT;
565 goto end;
566 }
567
568 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
569 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
570 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
571 pr_err("Invalid _PSD:coord_type\n");
572 result = -EFAULT;
573 goto end;
574 }
575end:
576 kfree(buffer.pointer);
577 return result;
578}
579EXPORT_SYMBOL(acpi_processor_get_psd);
580
581int acpi_processor_preregister_performance(
582 struct acpi_processor_performance __percpu *performance)
583{
584 int count_target;
585 int retval = 0;
586 unsigned int i, j;
587 cpumask_var_t covered_cpus;
588 struct acpi_processor *pr;
589 struct acpi_psd_package *pdomain;
590 struct acpi_processor *match_pr;
591 struct acpi_psd_package *match_pdomain;
592
593 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
594 return -ENOMEM;
595
596 mutex_lock(&performance_mutex);
597
598 /*
599 * Check if another driver has already registered, and abort before
600 * changing pr->performance if it has. Check input data as well.
601 */
602 for_each_possible_cpu(i) {
603 pr = per_cpu(processors, i);
604 if (!pr) {
605 /* Look only at processors in ACPI namespace */
606 continue;
607 }
608
609 if (pr->performance) {
610 retval = -EBUSY;
611 goto err_out;
612 }
613
614 if (!performance || !per_cpu_ptr(performance, i)) {
615 retval = -EINVAL;
616 goto err_out;
617 }
618 }
619
620 /* Call _PSD for all CPUs */
621 for_each_possible_cpu(i) {
622 pr = per_cpu(processors, i);
623 if (!pr)
624 continue;
625
626 pr->performance = per_cpu_ptr(performance, i);
627 pdomain = &(pr->performance->domain_info);
628 if (acpi_processor_get_psd(pr->handle, pdomain)) {
629 retval = -EINVAL;
630 continue;
631 }
632 }
633 if (retval)
634 goto err_ret;
635
636 /*
637 * Now that we have _PSD data from all CPUs, lets setup P-state
638 * domain info.
639 */
640 for_each_possible_cpu(i) {
641 pr = per_cpu(processors, i);
642 if (!pr)
643 continue;
644
645 if (cpumask_test_cpu(i, covered_cpus))
646 continue;
647
648 pdomain = &(pr->performance->domain_info);
649 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
650 cpumask_set_cpu(i, covered_cpus);
651 if (pdomain->num_processors <= 1)
652 continue;
653
654 /* Validate the Domain info */
655 count_target = pdomain->num_processors;
656 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
657 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
658 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
659 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
660 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
661 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
662
663 for_each_possible_cpu(j) {
664 if (i == j)
665 continue;
666
667 match_pr = per_cpu(processors, j);
668 if (!match_pr)
669 continue;
670
671 match_pdomain = &(match_pr->performance->domain_info);
672 if (match_pdomain->domain != pdomain->domain)
673 continue;
674
675 /* Here i and j are in the same domain */
676
677 if (match_pdomain->num_processors != count_target) {
678 retval = -EINVAL;
679 goto err_ret;
680 }
681
682 if (pdomain->coord_type != match_pdomain->coord_type) {
683 retval = -EINVAL;
684 goto err_ret;
685 }
686
687 cpumask_set_cpu(j, covered_cpus);
688 cpumask_set_cpu(j, pr->performance->shared_cpu_map);
689 }
690
691 for_each_possible_cpu(j) {
692 if (i == j)
693 continue;
694
695 match_pr = per_cpu(processors, j);
696 if (!match_pr)
697 continue;
698
699 match_pdomain = &(match_pr->performance->domain_info);
700 if (match_pdomain->domain != pdomain->domain)
701 continue;
702
703 match_pr->performance->shared_type =
704 pr->performance->shared_type;
705 cpumask_copy(match_pr->performance->shared_cpu_map,
706 pr->performance->shared_cpu_map);
707 }
708 }
709
710err_ret:
711 for_each_possible_cpu(i) {
712 pr = per_cpu(processors, i);
713 if (!pr || !pr->performance)
714 continue;
715
716 /* Assume no coordination on any error parsing domain info */
717 if (retval) {
718 cpumask_clear(pr->performance->shared_cpu_map);
719 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
720 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE;
721 }
722 pr->performance = NULL; /* Will be set for real in register */
723 }
724
725err_out:
726 mutex_unlock(&performance_mutex);
727 free_cpumask_var(covered_cpus);
728 return retval;
729}
730EXPORT_SYMBOL(acpi_processor_preregister_performance);
731
732int acpi_processor_register_performance(struct acpi_processor_performance
733 *performance, unsigned int cpu)
734{
735 struct acpi_processor *pr;
736
737 if (!acpi_processor_cpufreq_init)
738 return -EINVAL;
739
740 mutex_lock(&performance_mutex);
741
742 pr = per_cpu(processors, cpu);
743 if (!pr) {
744 mutex_unlock(&performance_mutex);
745 return -ENODEV;
746 }
747
748 if (pr->performance) {
749 mutex_unlock(&performance_mutex);
750 return -EBUSY;
751 }
752
753 WARN_ON(!performance);
754
755 pr->performance = performance;
756
757 if (acpi_processor_get_performance_info(pr)) {
758 pr->performance = NULL;
759 mutex_unlock(&performance_mutex);
760 return -EIO;
761 }
762
763 mutex_unlock(&performance_mutex);
764 return 0;
765}
766EXPORT_SYMBOL(acpi_processor_register_performance);
767
768void acpi_processor_unregister_performance(unsigned int cpu)
769{
770 struct acpi_processor *pr;
771
772 mutex_lock(&performance_mutex);
773
774 pr = per_cpu(processors, cpu);
775 if (!pr)
776 goto unlock;
777
778 if (pr->performance)
779 kfree(pr->performance->states);
780
781 pr->performance = NULL;
782
783unlock:
784 mutex_unlock(&performance_mutex);
785}
786EXPORT_SYMBOL(acpi_processor_unregister_performance);
787#endif
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9 * - Added processor hotplug support
10 */
11
12#define pr_fmt(fmt) "ACPI: " fmt
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/cpufreq.h>
18#include <linux/slab.h>
19#include <linux/acpi.h>
20#include <acpi/processor.h>
21#ifdef CONFIG_X86
22#include <asm/cpufeature.h>
23#endif
24
25#define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
26
27static DEFINE_MUTEX(performance_mutex);
28
29/*
30 * _PPC support is implemented as a CPUfreq policy notifier:
31 * This means each time a CPUfreq driver registered also with
32 * the ACPI core is asked to change the speed policy, the maximum
33 * value is adjusted so that it is within the platform limit.
34 *
35 * Also, when a new platform limit value is detected, the CPUfreq
36 * policy is adjusted accordingly.
37 */
38
39/* ignore_ppc:
40 * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
41 * ignore _PPC
42 * 0 -> cpufreq low level drivers initialized -> consider _PPC values
43 * 1 -> ignore _PPC totally -> forced by user through boot param
44 */
45static int ignore_ppc = -1;
46module_param(ignore_ppc, int, 0644);
47MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
48 "limited by BIOS, this should help");
49
50static bool acpi_processor_ppc_in_use;
51
52static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
53{
54 acpi_status status = 0;
55 unsigned long long ppc = 0;
56 int ret;
57
58 if (!pr)
59 return -EINVAL;
60
61 /*
62 * _PPC indicates the maximum state currently supported by the platform
63 * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
64 */
65 status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
66 if (status != AE_NOT_FOUND) {
67 acpi_processor_ppc_in_use = true;
68
69 if (ACPI_FAILURE(status)) {
70 acpi_evaluation_failure_warn(pr->handle, "_PPC", status);
71 return -ENODEV;
72 }
73 }
74
75 pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
76 (int)ppc, ppc ? "" : "not");
77
78 pr->performance_platform_limit = (int)ppc;
79
80 if (ppc >= pr->performance->state_count ||
81 unlikely(!freq_qos_request_active(&pr->perflib_req)))
82 return 0;
83
84 ret = freq_qos_update_request(&pr->perflib_req,
85 pr->performance->states[ppc].core_frequency * 1000);
86 if (ret < 0) {
87 pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n",
88 pr->id, ret);
89 }
90
91 return 0;
92}
93
94#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
95/*
96 * acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status
97 * @handle: ACPI processor handle
98 * @status: the status code of _PPC evaluation
99 * 0: success. OSPM is now using the performance state specified.
100 * 1: failure. OSPM has not changed the number of P-states in use
101 */
102static void acpi_processor_ppc_ost(acpi_handle handle, int status)
103{
104 if (acpi_has_method(handle, "_OST"))
105 acpi_evaluate_ost(handle, ACPI_PROCESSOR_NOTIFY_PERFORMANCE,
106 status, NULL);
107}
108
109void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
110{
111 int ret;
112
113 if (ignore_ppc || !pr->performance) {
114 /*
115 * Only when it is notification event, the _OST object
116 * will be evaluated. Otherwise it is skipped.
117 */
118 if (event_flag)
119 acpi_processor_ppc_ost(pr->handle, 1);
120 return;
121 }
122
123 ret = acpi_processor_get_platform_limit(pr);
124 /*
125 * Only when it is notification event, the _OST object
126 * will be evaluated. Otherwise it is skipped.
127 */
128 if (event_flag) {
129 if (ret < 0)
130 acpi_processor_ppc_ost(pr->handle, 1);
131 else
132 acpi_processor_ppc_ost(pr->handle, 0);
133 }
134 if (ret >= 0)
135 cpufreq_update_limits(pr->id);
136}
137
138int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
139{
140 struct acpi_processor *pr;
141
142 pr = per_cpu(processors, cpu);
143 if (!pr || !pr->performance || !pr->performance->state_count)
144 return -ENODEV;
145 *limit = pr->performance->states[pr->performance_platform_limit].
146 core_frequency * 1000;
147 return 0;
148}
149EXPORT_SYMBOL(acpi_processor_get_bios_limit);
150
151void acpi_processor_ignore_ppc_init(void)
152{
153 if (ignore_ppc < 0)
154 ignore_ppc = 0;
155}
156
157void acpi_processor_ppc_init(struct cpufreq_policy *policy)
158{
159 unsigned int cpu;
160
161 for_each_cpu(cpu, policy->related_cpus) {
162 struct acpi_processor *pr = per_cpu(processors, cpu);
163 int ret;
164
165 if (!pr)
166 continue;
167
168 ret = freq_qos_add_request(&policy->constraints,
169 &pr->perflib_req,
170 FREQ_QOS_MAX, INT_MAX);
171 if (ret < 0)
172 pr_err("Failed to add freq constraint for CPU%d (%d)\n",
173 cpu, ret);
174 }
175}
176
177void acpi_processor_ppc_exit(struct cpufreq_policy *policy)
178{
179 unsigned int cpu;
180
181 for_each_cpu(cpu, policy->related_cpus) {
182 struct acpi_processor *pr = per_cpu(processors, cpu);
183
184 if (pr)
185 freq_qos_remove_request(&pr->perflib_req);
186 }
187}
188
189static int acpi_processor_get_performance_control(struct acpi_processor *pr)
190{
191 int result = 0;
192 acpi_status status = 0;
193 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
194 union acpi_object *pct = NULL;
195 union acpi_object obj = { 0 };
196
197 status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
198 if (ACPI_FAILURE(status)) {
199 acpi_evaluation_failure_warn(pr->handle, "_PCT", status);
200 return -ENODEV;
201 }
202
203 pct = (union acpi_object *)buffer.pointer;
204 if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
205 || (pct->package.count != 2)) {
206 pr_err("Invalid _PCT data\n");
207 result = -EFAULT;
208 goto end;
209 }
210
211 /*
212 * control_register
213 */
214
215 obj = pct->package.elements[0];
216
217 if ((obj.type != ACPI_TYPE_BUFFER)
218 || (obj.buffer.length < sizeof(struct acpi_pct_register))
219 || (obj.buffer.pointer == NULL)) {
220 pr_err("Invalid _PCT data (control_register)\n");
221 result = -EFAULT;
222 goto end;
223 }
224 memcpy(&pr->performance->control_register, obj.buffer.pointer,
225 sizeof(struct acpi_pct_register));
226
227 /*
228 * status_register
229 */
230
231 obj = pct->package.elements[1];
232
233 if ((obj.type != ACPI_TYPE_BUFFER)
234 || (obj.buffer.length < sizeof(struct acpi_pct_register))
235 || (obj.buffer.pointer == NULL)) {
236 pr_err("Invalid _PCT data (status_register)\n");
237 result = -EFAULT;
238 goto end;
239 }
240
241 memcpy(&pr->performance->status_register, obj.buffer.pointer,
242 sizeof(struct acpi_pct_register));
243
244end:
245 kfree(buffer.pointer);
246
247 return result;
248}
249
250#ifdef CONFIG_X86
251/*
252 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding
253 * in their ACPI data. Calculate the real values and fix up the _PSS data.
254 */
255static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
256{
257 u32 hi, lo, fid, did;
258 int index = px->control & 0x00000007;
259
260 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
261 return;
262
263 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
264 || boot_cpu_data.x86 == 0x11) {
265 rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
266 /*
267 * MSR C001_0064+:
268 * Bit 63: PstateEn. Read-write. If set, the P-state is valid.
269 */
270 if (!(hi & BIT(31)))
271 return;
272
273 fid = lo & 0x3f;
274 did = (lo >> 6) & 7;
275 if (boot_cpu_data.x86 == 0x10)
276 px->core_frequency = (100 * (fid + 0x10)) >> did;
277 else
278 px->core_frequency = (100 * (fid + 8)) >> did;
279 }
280}
281#else
282static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {};
283#endif
284
285static int acpi_processor_get_performance_states(struct acpi_processor *pr)
286{
287 int result = 0;
288 acpi_status status = AE_OK;
289 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
290 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
291 struct acpi_buffer state = { 0, NULL };
292 union acpi_object *pss = NULL;
293 int i;
294 int last_invalid = -1;
295
296 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
297 if (ACPI_FAILURE(status)) {
298 acpi_evaluation_failure_warn(pr->handle, "_PSS", status);
299 return -ENODEV;
300 }
301
302 pss = buffer.pointer;
303 if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
304 pr_err("Invalid _PSS data\n");
305 result = -EFAULT;
306 goto end;
307 }
308
309 acpi_handle_debug(pr->handle, "Found %d performance states\n",
310 pss->package.count);
311
312 pr->performance->state_count = pss->package.count;
313 pr->performance->states =
314 kmalloc_array(pss->package.count,
315 sizeof(struct acpi_processor_px),
316 GFP_KERNEL);
317 if (!pr->performance->states) {
318 result = -ENOMEM;
319 goto end;
320 }
321
322 for (i = 0; i < pr->performance->state_count; i++) {
323
324 struct acpi_processor_px *px = &(pr->performance->states[i]);
325
326 state.length = sizeof(struct acpi_processor_px);
327 state.pointer = px;
328
329 acpi_handle_debug(pr->handle, "Extracting state %d\n", i);
330
331 status = acpi_extract_package(&(pss->package.elements[i]),
332 &format, &state);
333 if (ACPI_FAILURE(status)) {
334 acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n",
335 acpi_format_exception(status));
336 result = -EFAULT;
337 kfree(pr->performance->states);
338 goto end;
339 }
340
341 amd_fixup_frequency(px, i);
342
343 acpi_handle_debug(pr->handle,
344 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
345 i,
346 (u32) px->core_frequency,
347 (u32) px->power,
348 (u32) px->transition_latency,
349 (u32) px->bus_master_latency,
350 (u32) px->control, (u32) px->status);
351
352 /*
353 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq
354 */
355 if (!px->core_frequency ||
356 ((u32)(px->core_frequency * 1000) !=
357 (px->core_frequency * 1000))) {
358 pr_err(FW_BUG
359 "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n",
360 pr->id, px->core_frequency);
361 if (last_invalid == -1)
362 last_invalid = i;
363 } else {
364 if (last_invalid != -1) {
365 /*
366 * Copy this valid entry over last_invalid entry
367 */
368 memcpy(&(pr->performance->states[last_invalid]),
369 px, sizeof(struct acpi_processor_px));
370 ++last_invalid;
371 }
372 }
373 }
374
375 if (last_invalid == 0) {
376 pr_err(FW_BUG
377 "No valid BIOS _PSS frequency found for processor %d\n", pr->id);
378 result = -EFAULT;
379 kfree(pr->performance->states);
380 pr->performance->states = NULL;
381 }
382
383 if (last_invalid > 0)
384 pr->performance->state_count = last_invalid;
385
386end:
387 kfree(buffer.pointer);
388
389 return result;
390}
391
392int acpi_processor_get_performance_info(struct acpi_processor *pr)
393{
394 int result = 0;
395
396 if (!pr || !pr->performance || !pr->handle)
397 return -EINVAL;
398
399 if (!acpi_has_method(pr->handle, "_PCT")) {
400 acpi_handle_debug(pr->handle,
401 "ACPI-based processor performance control unavailable\n");
402 return -ENODEV;
403 }
404
405 result = acpi_processor_get_performance_control(pr);
406 if (result)
407 goto update_bios;
408
409 result = acpi_processor_get_performance_states(pr);
410 if (result)
411 goto update_bios;
412
413 /* We need to call _PPC once when cpufreq starts */
414 if (ignore_ppc != 1)
415 result = acpi_processor_get_platform_limit(pr);
416
417 return result;
418
419 /*
420 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
421 * the BIOS is older than the CPU and does not know its frequencies
422 */
423 update_bios:
424#ifdef CONFIG_X86
425 if (acpi_has_method(pr->handle, "_PPC")) {
426 if(boot_cpu_has(X86_FEATURE_EST))
427 pr_warn(FW_BUG "BIOS needs update for CPU "
428 "frequency support\n");
429 }
430#endif
431 return result;
432}
433EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info);
434
435int acpi_processor_pstate_control(void)
436{
437 acpi_status status;
438
439 if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control)
440 return 0;
441
442 pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n",
443 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command);
444
445 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
446 (u32)acpi_gbl_FADT.pstate_control, 8);
447 if (ACPI_SUCCESS(status))
448 return 1;
449
450 pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n",
451 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command,
452 acpi_format_exception(status));
453 return -EIO;
454}
455
456int acpi_processor_notify_smm(struct module *calling_module)
457{
458 static int is_done;
459 int result;
460
461 if (!acpi_processor_cpufreq_init)
462 return -EBUSY;
463
464 if (!try_module_get(calling_module))
465 return -EINVAL;
466
467 /* is_done is set to negative if an error occurred,
468 * and to postitive if _no_ error occurred, but SMM
469 * was already notified. This avoids double notification
470 * which might lead to unexpected results...
471 */
472 if (is_done > 0) {
473 module_put(calling_module);
474 return 0;
475 } else if (is_done < 0) {
476 module_put(calling_module);
477 return is_done;
478 }
479
480 is_done = -EIO;
481
482 result = acpi_processor_pstate_control();
483 if (!result) {
484 pr_debug("No SMI port or pstate_control\n");
485 module_put(calling_module);
486 return 0;
487 }
488 if (result < 0) {
489 module_put(calling_module);
490 return result;
491 }
492
493 /* Success. If there's no _PPC, we need to fear nothing, so
494 * we can allow the cpufreq driver to be rmmod'ed. */
495 is_done = 1;
496
497 if (!acpi_processor_ppc_in_use)
498 module_put(calling_module);
499
500 return 0;
501}
502
503EXPORT_SYMBOL(acpi_processor_notify_smm);
504
505int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
506{
507 int result = 0;
508 acpi_status status = AE_OK;
509 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
510 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
511 struct acpi_buffer state = {0, NULL};
512 union acpi_object *psd = NULL;
513
514 status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer);
515 if (ACPI_FAILURE(status)) {
516 return -ENODEV;
517 }
518
519 psd = buffer.pointer;
520 if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
521 pr_err("Invalid _PSD data\n");
522 result = -EFAULT;
523 goto end;
524 }
525
526 if (psd->package.count != 1) {
527 pr_err("Invalid _PSD data\n");
528 result = -EFAULT;
529 goto end;
530 }
531
532 state.length = sizeof(struct acpi_psd_package);
533 state.pointer = pdomain;
534
535 status = acpi_extract_package(&(psd->package.elements[0]),
536 &format, &state);
537 if (ACPI_FAILURE(status)) {
538 pr_err("Invalid _PSD data\n");
539 result = -EFAULT;
540 goto end;
541 }
542
543 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
544 pr_err("Unknown _PSD:num_entries\n");
545 result = -EFAULT;
546 goto end;
547 }
548
549 if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
550 pr_err("Unknown _PSD:revision\n");
551 result = -EFAULT;
552 goto end;
553 }
554
555 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
556 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
557 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
558 pr_err("Invalid _PSD:coord_type\n");
559 result = -EFAULT;
560 goto end;
561 }
562end:
563 kfree(buffer.pointer);
564 return result;
565}
566EXPORT_SYMBOL(acpi_processor_get_psd);
567
568int acpi_processor_preregister_performance(
569 struct acpi_processor_performance __percpu *performance)
570{
571 int count_target;
572 int retval = 0;
573 unsigned int i, j;
574 cpumask_var_t covered_cpus;
575 struct acpi_processor *pr;
576 struct acpi_psd_package *pdomain;
577 struct acpi_processor *match_pr;
578 struct acpi_psd_package *match_pdomain;
579
580 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
581 return -ENOMEM;
582
583 mutex_lock(&performance_mutex);
584
585 /*
586 * Check if another driver has already registered, and abort before
587 * changing pr->performance if it has. Check input data as well.
588 */
589 for_each_possible_cpu(i) {
590 pr = per_cpu(processors, i);
591 if (!pr) {
592 /* Look only at processors in ACPI namespace */
593 continue;
594 }
595
596 if (pr->performance) {
597 retval = -EBUSY;
598 goto err_out;
599 }
600
601 if (!performance || !per_cpu_ptr(performance, i)) {
602 retval = -EINVAL;
603 goto err_out;
604 }
605 }
606
607 /* Call _PSD for all CPUs */
608 for_each_possible_cpu(i) {
609 pr = per_cpu(processors, i);
610 if (!pr)
611 continue;
612
613 pr->performance = per_cpu_ptr(performance, i);
614 pdomain = &(pr->performance->domain_info);
615 if (acpi_processor_get_psd(pr->handle, pdomain)) {
616 retval = -EINVAL;
617 continue;
618 }
619 }
620 if (retval)
621 goto err_ret;
622
623 /*
624 * Now that we have _PSD data from all CPUs, lets setup P-state
625 * domain info.
626 */
627 for_each_possible_cpu(i) {
628 pr = per_cpu(processors, i);
629 if (!pr)
630 continue;
631
632 if (cpumask_test_cpu(i, covered_cpus))
633 continue;
634
635 pdomain = &(pr->performance->domain_info);
636 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
637 cpumask_set_cpu(i, covered_cpus);
638 if (pdomain->num_processors <= 1)
639 continue;
640
641 /* Validate the Domain info */
642 count_target = pdomain->num_processors;
643 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
644 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
645 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
646 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
647 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
648 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
649
650 for_each_possible_cpu(j) {
651 if (i == j)
652 continue;
653
654 match_pr = per_cpu(processors, j);
655 if (!match_pr)
656 continue;
657
658 match_pdomain = &(match_pr->performance->domain_info);
659 if (match_pdomain->domain != pdomain->domain)
660 continue;
661
662 /* Here i and j are in the same domain */
663
664 if (match_pdomain->num_processors != count_target) {
665 retval = -EINVAL;
666 goto err_ret;
667 }
668
669 if (pdomain->coord_type != match_pdomain->coord_type) {
670 retval = -EINVAL;
671 goto err_ret;
672 }
673
674 cpumask_set_cpu(j, covered_cpus);
675 cpumask_set_cpu(j, pr->performance->shared_cpu_map);
676 }
677
678 for_each_possible_cpu(j) {
679 if (i == j)
680 continue;
681
682 match_pr = per_cpu(processors, j);
683 if (!match_pr)
684 continue;
685
686 match_pdomain = &(match_pr->performance->domain_info);
687 if (match_pdomain->domain != pdomain->domain)
688 continue;
689
690 match_pr->performance->shared_type =
691 pr->performance->shared_type;
692 cpumask_copy(match_pr->performance->shared_cpu_map,
693 pr->performance->shared_cpu_map);
694 }
695 }
696
697err_ret:
698 for_each_possible_cpu(i) {
699 pr = per_cpu(processors, i);
700 if (!pr || !pr->performance)
701 continue;
702
703 /* Assume no coordination on any error parsing domain info */
704 if (retval) {
705 cpumask_clear(pr->performance->shared_cpu_map);
706 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
707 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE;
708 }
709 pr->performance = NULL; /* Will be set for real in register */
710 }
711
712err_out:
713 mutex_unlock(&performance_mutex);
714 free_cpumask_var(covered_cpus);
715 return retval;
716}
717EXPORT_SYMBOL(acpi_processor_preregister_performance);
718
719int
720acpi_processor_register_performance(struct acpi_processor_performance
721 *performance, unsigned int cpu)
722{
723 struct acpi_processor *pr;
724
725 if (!acpi_processor_cpufreq_init)
726 return -EINVAL;
727
728 mutex_lock(&performance_mutex);
729
730 pr = per_cpu(processors, cpu);
731 if (!pr) {
732 mutex_unlock(&performance_mutex);
733 return -ENODEV;
734 }
735
736 if (pr->performance) {
737 mutex_unlock(&performance_mutex);
738 return -EBUSY;
739 }
740
741 WARN_ON(!performance);
742
743 pr->performance = performance;
744
745 if (acpi_processor_get_performance_info(pr)) {
746 pr->performance = NULL;
747 mutex_unlock(&performance_mutex);
748 return -EIO;
749 }
750
751 mutex_unlock(&performance_mutex);
752 return 0;
753}
754
755EXPORT_SYMBOL(acpi_processor_register_performance);
756
757void acpi_processor_unregister_performance(unsigned int cpu)
758{
759 struct acpi_processor *pr;
760
761 mutex_lock(&performance_mutex);
762
763 pr = per_cpu(processors, cpu);
764 if (!pr) {
765 mutex_unlock(&performance_mutex);
766 return;
767 }
768
769 if (pr->performance)
770 kfree(pr->performance->states);
771 pr->performance = NULL;
772
773 mutex_unlock(&performance_mutex);
774
775 return;
776}
777
778EXPORT_SYMBOL(acpi_processor_unregister_performance);