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 s32 qos_value;
57 int index;
58 int ret;
59
60 if (!pr)
61 return -EINVAL;
62
63 /*
64 * _PPC indicates the maximum state currently supported by the platform
65 * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
66 */
67 status = acpi_evaluate_integer(handle: pr->handle, pathname: "_PPC", NULL, data: &ppc);
68 if (status != AE_NOT_FOUND) {
69 acpi_processor_ppc_in_use = true;
70
71 if (ACPI_FAILURE(status)) {
72 acpi_evaluation_failure_warn(handle: pr->handle, name: "_PPC", status);
73 return -ENODEV;
74 }
75 }
76
77 index = ppc;
78
79 if (pr->performance_platform_limit == index ||
80 ppc >= pr->performance->state_count)
81 return 0;
82
83 pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
84 index, index ? "is" : "is not");
85
86 pr->performance_platform_limit = index;
87
88 if (unlikely(!freq_qos_request_active(&pr->perflib_req)))
89 return 0;
90
91 /*
92 * If _PPC returns 0, it means that all of the available states can be
93 * used ("no limit").
94 */
95 if (index == 0)
96 qos_value = FREQ_QOS_MAX_DEFAULT_VALUE;
97 else
98 qos_value = pr->performance->states[index].core_frequency * 1000;
99
100 ret = freq_qos_update_request(req: &pr->perflib_req, new_value: qos_value);
101 if (ret < 0) {
102 pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n",
103 pr->id, ret);
104 }
105
106 return 0;
107}
108
109#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
110/*
111 * acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status
112 * @handle: ACPI processor handle
113 * @status: the status code of _PPC evaluation
114 * 0: success. OSPM is now using the performance state specified.
115 * 1: failure. OSPM has not changed the number of P-states in use
116 */
117static void acpi_processor_ppc_ost(acpi_handle handle, int status)
118{
119 if (acpi_has_method(handle, name: "_OST"))
120 acpi_evaluate_ost(handle, ACPI_PROCESSOR_NOTIFY_PERFORMANCE,
121 status_code: status, NULL);
122}
123
124void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
125{
126 int ret;
127
128 if (ignore_ppc || !pr->performance) {
129 /*
130 * Only when it is notification event, the _OST object
131 * will be evaluated. Otherwise it is skipped.
132 */
133 if (event_flag)
134 acpi_processor_ppc_ost(handle: pr->handle, status: 1);
135 return;
136 }
137
138 ret = acpi_processor_get_platform_limit(pr);
139 /*
140 * Only when it is notification event, the _OST object
141 * will be evaluated. Otherwise it is skipped.
142 */
143 if (event_flag) {
144 if (ret < 0)
145 acpi_processor_ppc_ost(handle: pr->handle, status: 1);
146 else
147 acpi_processor_ppc_ost(handle: pr->handle, status: 0);
148 }
149 if (ret >= 0)
150 cpufreq_update_limits(cpu: pr->id);
151}
152
153int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
154{
155 struct acpi_processor *pr;
156
157 pr = per_cpu(processors, cpu);
158 if (!pr || !pr->performance || !pr->performance->state_count)
159 return -ENODEV;
160
161 *limit = pr->performance->states[pr->performance_platform_limit].
162 core_frequency * 1000;
163 return 0;
164}
165EXPORT_SYMBOL(acpi_processor_get_bios_limit);
166
167void acpi_processor_ignore_ppc_init(void)
168{
169 if (ignore_ppc < 0)
170 ignore_ppc = 0;
171}
172
173void acpi_processor_ppc_init(struct cpufreq_policy *policy)
174{
175 unsigned int cpu;
176
177 for_each_cpu(cpu, policy->related_cpus) {
178 struct acpi_processor *pr = per_cpu(processors, cpu);
179 int ret;
180
181 if (!pr)
182 continue;
183
184 /*
185 * Reset performance_platform_limit in case there is a stale
186 * value in it, so as to make it match the "no limit" QoS value
187 * below.
188 */
189 pr->performance_platform_limit = 0;
190
191 ret = freq_qos_add_request(qos: &policy->constraints,
192 req: &pr->perflib_req, type: FREQ_QOS_MAX,
193 FREQ_QOS_MAX_DEFAULT_VALUE);
194 if (ret < 0)
195 pr_err("Failed to add freq constraint for CPU%d (%d)\n",
196 cpu, ret);
197 }
198}
199
200void acpi_processor_ppc_exit(struct cpufreq_policy *policy)
201{
202 unsigned int cpu;
203
204 for_each_cpu(cpu, policy->related_cpus) {
205 struct acpi_processor *pr = per_cpu(processors, cpu);
206
207 if (pr)
208 freq_qos_remove_request(req: &pr->perflib_req);
209 }
210}
211
212static int acpi_processor_get_performance_control(struct acpi_processor *pr)
213{
214 int result = 0;
215 acpi_status status = 0;
216 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
217 union acpi_object *pct = NULL;
218 union acpi_object obj = { 0 };
219
220 status = acpi_evaluate_object(object: pr->handle, pathname: "_PCT", NULL, return_object_buffer: &buffer);
221 if (ACPI_FAILURE(status)) {
222 acpi_evaluation_failure_warn(handle: pr->handle, name: "_PCT", status);
223 return -ENODEV;
224 }
225
226 pct = (union acpi_object *)buffer.pointer;
227 if (!pct || pct->type != ACPI_TYPE_PACKAGE || pct->package.count != 2) {
228 pr_err("Invalid _PCT data\n");
229 result = -EFAULT;
230 goto end;
231 }
232
233 /*
234 * control_register
235 */
236
237 obj = pct->package.elements[0];
238
239 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER ||
240 obj.buffer.length < sizeof(struct acpi_pct_register)) {
241 pr_err("Invalid _PCT data (control_register)\n");
242 result = -EFAULT;
243 goto end;
244 }
245 memcpy(&pr->performance->control_register, obj.buffer.pointer,
246 sizeof(struct acpi_pct_register));
247
248 /*
249 * status_register
250 */
251
252 obj = pct->package.elements[1];
253
254 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER ||
255 obj.buffer.length < sizeof(struct acpi_pct_register)) {
256 pr_err("Invalid _PCT data (status_register)\n");
257 result = -EFAULT;
258 goto end;
259 }
260
261 memcpy(&pr->performance->status_register, obj.buffer.pointer,
262 sizeof(struct acpi_pct_register));
263
264end:
265 kfree(objp: buffer.pointer);
266
267 return result;
268}
269
270#ifdef CONFIG_X86
271/*
272 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding
273 * in their ACPI data. Calculate the real values and fix up the _PSS data.
274 */
275static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
276{
277 u32 hi, lo, fid, did;
278 int index = px->control & 0x00000007;
279
280 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
281 return;
282
283 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) ||
284 boot_cpu_data.x86 == 0x11) {
285 rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
286 /*
287 * MSR C001_0064+:
288 * Bit 63: PstateEn. Read-write. If set, the P-state is valid.
289 */
290 if (!(hi & BIT(31)))
291 return;
292
293 fid = lo & 0x3f;
294 did = (lo >> 6) & 7;
295 if (boot_cpu_data.x86 == 0x10)
296 px->core_frequency = (100 * (fid + 0x10)) >> did;
297 else
298 px->core_frequency = (100 * (fid + 8)) >> did;
299 }
300}
301#else
302static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {};
303#endif
304
305static int acpi_processor_get_performance_states(struct acpi_processor *pr)
306{
307 int result = 0;
308 acpi_status status = AE_OK;
309 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
310 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
311 struct acpi_buffer state = { 0, NULL };
312 union acpi_object *pss = NULL;
313 int i;
314 int last_invalid = -1;
315
316 status = acpi_evaluate_object(object: pr->handle, pathname: "_PSS", NULL, return_object_buffer: &buffer);
317 if (ACPI_FAILURE(status)) {
318 acpi_evaluation_failure_warn(handle: pr->handle, name: "_PSS", status);
319 return -ENODEV;
320 }
321
322 pss = buffer.pointer;
323 if (!pss || pss->type != ACPI_TYPE_PACKAGE) {
324 pr_err("Invalid _PSS data\n");
325 result = -EFAULT;
326 goto end;
327 }
328
329 acpi_handle_debug(pr->handle, "Found %d performance states\n",
330 pss->package.count);
331
332 pr->performance->state_count = pss->package.count;
333 pr->performance->states =
334 kmalloc_array(n: pss->package.count,
335 size: sizeof(struct acpi_processor_px),
336 GFP_KERNEL);
337 if (!pr->performance->states) {
338 result = -ENOMEM;
339 goto end;
340 }
341
342 for (i = 0; i < pr->performance->state_count; i++) {
343
344 struct acpi_processor_px *px = &(pr->performance->states[i]);
345
346 state.length = sizeof(struct acpi_processor_px);
347 state.pointer = px;
348
349 acpi_handle_debug(pr->handle, "Extracting state %d\n", i);
350
351 status = acpi_extract_package(package: &(pss->package.elements[i]),
352 format: &format, buffer: &state);
353 if (ACPI_FAILURE(status)) {
354 acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n",
355 acpi_format_exception(status));
356 result = -EFAULT;
357 kfree(objp: pr->performance->states);
358 goto end;
359 }
360
361 amd_fixup_frequency(px, i);
362
363 acpi_handle_debug(pr->handle,
364 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
365 i,
366 (u32) px->core_frequency,
367 (u32) px->power,
368 (u32) px->transition_latency,
369 (u32) px->bus_master_latency,
370 (u32) px->control, (u32) px->status);
371
372 /*
373 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq
374 */
375 if (!px->core_frequency ||
376 (u32)(px->core_frequency * 1000) != px->core_frequency * 1000) {
377 pr_err(FW_BUG
378 "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n",
379 pr->id, px->core_frequency);
380 if (last_invalid == -1)
381 last_invalid = i;
382 } else {
383 if (last_invalid != -1) {
384 /*
385 * Copy this valid entry over last_invalid entry
386 */
387 memcpy(&(pr->performance->states[last_invalid]),
388 px, sizeof(struct acpi_processor_px));
389 ++last_invalid;
390 }
391 }
392 }
393
394 if (last_invalid == 0) {
395 pr_err(FW_BUG
396 "No valid BIOS _PSS frequency found for processor %d\n", pr->id);
397 result = -EFAULT;
398 kfree(objp: pr->performance->states);
399 pr->performance->states = NULL;
400 }
401
402 if (last_invalid > 0)
403 pr->performance->state_count = last_invalid;
404
405end:
406 kfree(objp: buffer.pointer);
407
408 return result;
409}
410
411int acpi_processor_get_performance_info(struct acpi_processor *pr)
412{
413 int result = 0;
414
415 if (!pr || !pr->performance || !pr->handle)
416 return -EINVAL;
417
418 if (!acpi_has_method(handle: pr->handle, name: "_PCT")) {
419 acpi_handle_debug(pr->handle,
420 "ACPI-based processor performance control unavailable\n");
421 return -ENODEV;
422 }
423
424 result = acpi_processor_get_performance_control(pr);
425 if (result)
426 goto update_bios;
427
428 result = acpi_processor_get_performance_states(pr);
429 if (result)
430 goto update_bios;
431
432 /* We need to call _PPC once when cpufreq starts */
433 if (ignore_ppc != 1)
434 result = acpi_processor_get_platform_limit(pr);
435
436 return result;
437
438 /*
439 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
440 * the BIOS is older than the CPU and does not know its frequencies
441 */
442 update_bios:
443#ifdef CONFIG_X86
444 if (acpi_has_method(handle: pr->handle, name: "_PPC")) {
445 if(boot_cpu_has(X86_FEATURE_EST))
446 pr_warn(FW_BUG "BIOS needs update for CPU "
447 "frequency support\n");
448 }
449#endif
450 return result;
451}
452EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info);
453
454int acpi_processor_pstate_control(void)
455{
456 acpi_status status;
457
458 if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control)
459 return 0;
460
461 pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n",
462 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command);
463
464 status = acpi_os_write_port(address: acpi_gbl_FADT.smi_command,
465 value: (u32)acpi_gbl_FADT.pstate_control, width: 8);
466 if (ACPI_SUCCESS(status))
467 return 1;
468
469 pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n",
470 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command,
471 acpi_format_exception(status));
472 return -EIO;
473}
474
475int acpi_processor_notify_smm(struct module *calling_module)
476{
477 static int is_done;
478 int result = 0;
479
480 if (!acpi_processor_cpufreq_init)
481 return -EBUSY;
482
483 if (!try_module_get(module: calling_module))
484 return -EINVAL;
485
486 /*
487 * is_done is set to negative if an error occurs and to 1 if no error
488 * occurrs, but SMM has been notified already. This avoids repeated
489 * notification which might lead to unexpected results.
490 */
491 if (is_done != 0) {
492 if (is_done < 0)
493 result = is_done;
494
495 goto out_put;
496 }
497
498 result = acpi_processor_pstate_control();
499 if (result <= 0) {
500 if (result) {
501 is_done = result;
502 } else {
503 pr_debug("No SMI port or pstate_control\n");
504 is_done = 1;
505 }
506 goto out_put;
507 }
508
509 is_done = 1;
510 /*
511 * Success. If there _PPC, unloading the cpufreq driver would be risky,
512 * so disallow it in that case.
513 */
514 if (acpi_processor_ppc_in_use)
515 return 0;
516
517out_put:
518 module_put(module: calling_module);
519 return result;
520}
521EXPORT_SYMBOL(acpi_processor_notify_smm);
522
523int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
524{
525 int result = 0;
526 acpi_status status = AE_OK;
527 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
528 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
529 struct acpi_buffer state = {0, NULL};
530 union acpi_object *psd = NULL;
531
532 status = acpi_evaluate_object(object: handle, pathname: "_PSD", NULL, return_object_buffer: &buffer);
533 if (ACPI_FAILURE(status)) {
534 return -ENODEV;
535 }
536
537 psd = buffer.pointer;
538 if (!psd || psd->type != ACPI_TYPE_PACKAGE) {
539 pr_err("Invalid _PSD data\n");
540 result = -EFAULT;
541 goto end;
542 }
543
544 if (psd->package.count != 1) {
545 pr_err("Invalid _PSD data\n");
546 result = -EFAULT;
547 goto end;
548 }
549
550 state.length = sizeof(struct acpi_psd_package);
551 state.pointer = pdomain;
552
553 status = acpi_extract_package(package: &(psd->package.elements[0]), format: &format, buffer: &state);
554 if (ACPI_FAILURE(status)) {
555 pr_err("Invalid _PSD data\n");
556 result = -EFAULT;
557 goto end;
558 }
559
560 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
561 pr_err("Unknown _PSD:num_entries\n");
562 result = -EFAULT;
563 goto end;
564 }
565
566 if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
567 pr_err("Unknown _PSD:revision\n");
568 result = -EFAULT;
569 goto end;
570 }
571
572 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
573 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
574 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
575 pr_err("Invalid _PSD:coord_type\n");
576 result = -EFAULT;
577 goto end;
578 }
579end:
580 kfree(objp: buffer.pointer);
581 return result;
582}
583EXPORT_SYMBOL(acpi_processor_get_psd);
584
585int acpi_processor_preregister_performance(
586 struct acpi_processor_performance __percpu *performance)
587{
588 int count_target;
589 int retval = 0;
590 unsigned int i, j;
591 cpumask_var_t covered_cpus;
592 struct acpi_processor *pr;
593 struct acpi_psd_package *pdomain;
594 struct acpi_processor *match_pr;
595 struct acpi_psd_package *match_pdomain;
596
597 if (!zalloc_cpumask_var(mask: &covered_cpus, GFP_KERNEL))
598 return -ENOMEM;
599
600 mutex_lock(&performance_mutex);
601
602 /*
603 * Check if another driver has already registered, and abort before
604 * changing pr->performance if it has. Check input data as well.
605 */
606 for_each_possible_cpu(i) {
607 pr = per_cpu(processors, i);
608 if (!pr) {
609 /* Look only at processors in ACPI namespace */
610 continue;
611 }
612
613 if (pr->performance) {
614 retval = -EBUSY;
615 goto err_out;
616 }
617
618 if (!performance || !per_cpu_ptr(performance, i)) {
619 retval = -EINVAL;
620 goto err_out;
621 }
622 }
623
624 /* Call _PSD for all CPUs */
625 for_each_possible_cpu(i) {
626 pr = per_cpu(processors, i);
627 if (!pr)
628 continue;
629
630 pr->performance = per_cpu_ptr(performance, i);
631 pdomain = &(pr->performance->domain_info);
632 if (acpi_processor_get_psd(pr->handle, pdomain)) {
633 retval = -EINVAL;
634 continue;
635 }
636 }
637 if (retval)
638 goto err_ret;
639
640 /*
641 * Now that we have _PSD data from all CPUs, lets setup P-state
642 * domain info.
643 */
644 for_each_possible_cpu(i) {
645 pr = per_cpu(processors, i);
646 if (!pr)
647 continue;
648
649 if (cpumask_test_cpu(cpu: i, cpumask: covered_cpus))
650 continue;
651
652 pdomain = &(pr->performance->domain_info);
653 cpumask_set_cpu(cpu: i, dstp: pr->performance->shared_cpu_map);
654 cpumask_set_cpu(cpu: i, dstp: covered_cpus);
655 if (pdomain->num_processors <= 1)
656 continue;
657
658 /* Validate the Domain info */
659 count_target = pdomain->num_processors;
660 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
661 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
662 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
663 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
664 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
665 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
666
667 for_each_possible_cpu(j) {
668 if (i == j)
669 continue;
670
671 match_pr = per_cpu(processors, j);
672 if (!match_pr)
673 continue;
674
675 match_pdomain = &(match_pr->performance->domain_info);
676 if (match_pdomain->domain != pdomain->domain)
677 continue;
678
679 /* Here i and j are in the same domain */
680
681 if (match_pdomain->num_processors != count_target) {
682 retval = -EINVAL;
683 goto err_ret;
684 }
685
686 if (pdomain->coord_type != match_pdomain->coord_type) {
687 retval = -EINVAL;
688 goto err_ret;
689 }
690
691 cpumask_set_cpu(cpu: j, dstp: covered_cpus);
692 cpumask_set_cpu(cpu: j, dstp: pr->performance->shared_cpu_map);
693 }
694
695 for_each_possible_cpu(j) {
696 if (i == j)
697 continue;
698
699 match_pr = per_cpu(processors, j);
700 if (!match_pr)
701 continue;
702
703 match_pdomain = &(match_pr->performance->domain_info);
704 if (match_pdomain->domain != pdomain->domain)
705 continue;
706
707 match_pr->performance->shared_type =
708 pr->performance->shared_type;
709 cpumask_copy(dstp: match_pr->performance->shared_cpu_map,
710 srcp: pr->performance->shared_cpu_map);
711 }
712 }
713
714err_ret:
715 for_each_possible_cpu(i) {
716 pr = per_cpu(processors, i);
717 if (!pr || !pr->performance)
718 continue;
719
720 /* Assume no coordination on any error parsing domain info */
721 if (retval) {
722 cpumask_clear(dstp: pr->performance->shared_cpu_map);
723 cpumask_set_cpu(cpu: i, dstp: pr->performance->shared_cpu_map);
724 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE;
725 }
726 pr->performance = NULL; /* Will be set for real in register */
727 }
728
729err_out:
730 mutex_unlock(lock: &performance_mutex);
731 free_cpumask_var(mask: covered_cpus);
732 return retval;
733}
734EXPORT_SYMBOL(acpi_processor_preregister_performance);
735
736int acpi_processor_register_performance(struct acpi_processor_performance
737 *performance, unsigned int cpu)
738{
739 struct acpi_processor *pr;
740
741 if (!acpi_processor_cpufreq_init)
742 return -EINVAL;
743
744 mutex_lock(&performance_mutex);
745
746 pr = per_cpu(processors, cpu);
747 if (!pr) {
748 mutex_unlock(lock: &performance_mutex);
749 return -ENODEV;
750 }
751
752 if (pr->performance) {
753 mutex_unlock(lock: &performance_mutex);
754 return -EBUSY;
755 }
756
757 WARN_ON(!performance);
758
759 pr->performance = performance;
760
761 if (acpi_processor_get_performance_info(pr)) {
762 pr->performance = NULL;
763 mutex_unlock(lock: &performance_mutex);
764 return -EIO;
765 }
766
767 mutex_unlock(lock: &performance_mutex);
768 return 0;
769}
770EXPORT_SYMBOL(acpi_processor_register_performance);
771
772void acpi_processor_unregister_performance(unsigned int cpu)
773{
774 struct acpi_processor *pr;
775
776 mutex_lock(&performance_mutex);
777
778 pr = per_cpu(processors, cpu);
779 if (!pr)
780 goto unlock;
781
782 if (pr->performance)
783 kfree(objp: pr->performance->states);
784
785 pr->performance = NULL;
786
787unlock:
788 mutex_unlock(lock: &performance_mutex);
789}
790EXPORT_SYMBOL(acpi_processor_unregister_performance);
791

source code of linux/drivers/acpi/processor_perflib.c