cipso: unsigned buf_len cannot be negative
[linux-2.6/next.git] / drivers / acpi / processor_perflib.c
blobdbcf260ea93fce4d65b59dcd90c85d70f868c1b5
1 /*
2 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
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
11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or (at
16 * your option) any later version.
18 * This program is distributed in the hope that it will be useful, but
19 * WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
23 * You should have received a copy of the GNU General Public License along
24 * with this program; if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/cpufreq.h>
34 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
40 #endif
42 #ifdef CONFIG_X86
43 #include <asm/cpufeature.h>
44 #endif
46 #include <acpi/acpi_bus.h>
47 #include <acpi/processor.h>
49 #define ACPI_PROCESSOR_COMPONENT 0x01000000
50 #define ACPI_PROCESSOR_CLASS "processor"
51 #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
52 #define _COMPONENT ACPI_PROCESSOR_COMPONENT
53 ACPI_MODULE_NAME("processor_perflib");
55 static DEFINE_MUTEX(performance_mutex);
57 /* Use cpufreq debug layer for _PPC changes. */
58 #define cpufreq_printk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \
59 "cpufreq-core", msg)
62 * _PPC support is implemented as a CPUfreq policy notifier:
63 * This means each time a CPUfreq driver registered also with
64 * the ACPI core is asked to change the speed policy, the maximum
65 * value is adjusted so that it is within the platform limit.
67 * Also, when a new platform limit value is detected, the CPUfreq
68 * policy is adjusted accordingly.
71 /* ignore_ppc:
72 * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
73 * ignore _PPC
74 * 0 -> cpufreq low level drivers initialized -> consider _PPC values
75 * 1 -> ignore _PPC totally -> forced by user through boot param
77 static int ignore_ppc = -1;
78 module_param(ignore_ppc, int, 0644);
79 MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
80 "limited by BIOS, this should help");
82 #define PPC_REGISTERED 1
83 #define PPC_IN_USE 2
85 static int acpi_processor_ppc_status;
87 static int acpi_processor_ppc_notifier(struct notifier_block *nb,
88 unsigned long event, void *data)
90 struct cpufreq_policy *policy = data;
91 struct acpi_processor *pr;
92 unsigned int ppc = 0;
94 if (event == CPUFREQ_START && ignore_ppc <= 0) {
95 ignore_ppc = 0;
96 return 0;
99 if (ignore_ppc)
100 return 0;
102 if (event != CPUFREQ_INCOMPATIBLE)
103 return 0;
105 mutex_lock(&performance_mutex);
107 pr = per_cpu(processors, policy->cpu);
108 if (!pr || !pr->performance)
109 goto out;
111 ppc = (unsigned int)pr->performance_platform_limit;
113 if (ppc >= pr->performance->state_count)
114 goto out;
116 cpufreq_verify_within_limits(policy, 0,
117 pr->performance->states[ppc].
118 core_frequency * 1000);
120 out:
121 mutex_unlock(&performance_mutex);
123 return 0;
126 static struct notifier_block acpi_ppc_notifier_block = {
127 .notifier_call = acpi_processor_ppc_notifier,
130 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
132 acpi_status status = 0;
133 unsigned long long ppc = 0;
136 if (!pr)
137 return -EINVAL;
140 * _PPC indicates the maximum state currently supported by the platform
141 * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
143 status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
145 if (status != AE_NOT_FOUND)
146 acpi_processor_ppc_status |= PPC_IN_USE;
148 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
149 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PPC"));
150 return -ENODEV;
153 cpufreq_printk("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
154 (int)ppc, ppc ? "" : "not");
156 pr->performance_platform_limit = (int)ppc;
158 return 0;
161 int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
163 int ret;
165 if (ignore_ppc)
166 return 0;
168 ret = acpi_processor_get_platform_limit(pr);
170 if (ret < 0)
171 return (ret);
172 else
173 return cpufreq_update_policy(pr->id);
176 void acpi_processor_ppc_init(void)
178 if (!cpufreq_register_notifier
179 (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
180 acpi_processor_ppc_status |= PPC_REGISTERED;
181 else
182 printk(KERN_DEBUG
183 "Warning: Processor Platform Limit not supported.\n");
186 void acpi_processor_ppc_exit(void)
188 if (acpi_processor_ppc_status & PPC_REGISTERED)
189 cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
190 CPUFREQ_POLICY_NOTIFIER);
192 acpi_processor_ppc_status &= ~PPC_REGISTERED;
195 static int acpi_processor_get_performance_control(struct acpi_processor *pr)
197 int result = 0;
198 acpi_status status = 0;
199 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
200 union acpi_object *pct = NULL;
201 union acpi_object obj = { 0 };
204 status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
205 if (ACPI_FAILURE(status)) {
206 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PCT"));
207 return -ENODEV;
210 pct = (union acpi_object *)buffer.pointer;
211 if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
212 || (pct->package.count != 2)) {
213 printk(KERN_ERR PREFIX "Invalid _PCT data\n");
214 result = -EFAULT;
215 goto end;
219 * control_register
222 obj = pct->package.elements[0];
224 if ((obj.type != ACPI_TYPE_BUFFER)
225 || (obj.buffer.length < sizeof(struct acpi_pct_register))
226 || (obj.buffer.pointer == NULL)) {
227 printk(KERN_ERR PREFIX "Invalid _PCT data (control_register)\n");
228 result = -EFAULT;
229 goto end;
231 memcpy(&pr->performance->control_register, obj.buffer.pointer,
232 sizeof(struct acpi_pct_register));
235 * status_register
238 obj = pct->package.elements[1];
240 if ((obj.type != ACPI_TYPE_BUFFER)
241 || (obj.buffer.length < sizeof(struct acpi_pct_register))
242 || (obj.buffer.pointer == NULL)) {
243 printk(KERN_ERR PREFIX "Invalid _PCT data (status_register)\n");
244 result = -EFAULT;
245 goto end;
248 memcpy(&pr->performance->status_register, obj.buffer.pointer,
249 sizeof(struct acpi_pct_register));
251 end:
252 kfree(buffer.pointer);
254 return result;
257 static int acpi_processor_get_performance_states(struct acpi_processor *pr)
259 int result = 0;
260 acpi_status status = AE_OK;
261 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
262 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
263 struct acpi_buffer state = { 0, NULL };
264 union acpi_object *pss = NULL;
265 int i;
268 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
269 if (ACPI_FAILURE(status)) {
270 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PSS"));
271 return -ENODEV;
274 pss = buffer.pointer;
275 if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
276 printk(KERN_ERR PREFIX "Invalid _PSS data\n");
277 result = -EFAULT;
278 goto end;
281 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
282 pss->package.count));
284 pr->performance->state_count = pss->package.count;
285 pr->performance->states =
286 kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
287 GFP_KERNEL);
288 if (!pr->performance->states) {
289 result = -ENOMEM;
290 goto end;
293 for (i = 0; i < pr->performance->state_count; i++) {
295 struct acpi_processor_px *px = &(pr->performance->states[i]);
297 state.length = sizeof(struct acpi_processor_px);
298 state.pointer = px;
300 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
302 status = acpi_extract_package(&(pss->package.elements[i]),
303 &format, &state);
304 if (ACPI_FAILURE(status)) {
305 ACPI_EXCEPTION((AE_INFO, status, "Invalid _PSS data"));
306 result = -EFAULT;
307 kfree(pr->performance->states);
308 goto end;
311 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
312 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
314 (u32) px->core_frequency,
315 (u32) px->power,
316 (u32) px->transition_latency,
317 (u32) px->bus_master_latency,
318 (u32) px->control, (u32) px->status));
320 if (!px->core_frequency) {
321 printk(KERN_ERR PREFIX
322 "Invalid _PSS data: freq is zero\n");
323 result = -EFAULT;
324 kfree(pr->performance->states);
325 goto end;
329 end:
330 kfree(buffer.pointer);
332 return result;
335 static int acpi_processor_get_performance_info(struct acpi_processor *pr)
337 int result = 0;
338 acpi_status status = AE_OK;
339 acpi_handle handle = NULL;
341 if (!pr || !pr->performance || !pr->handle)
342 return -EINVAL;
344 status = acpi_get_handle(pr->handle, "_PCT", &handle);
345 if (ACPI_FAILURE(status)) {
346 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
347 "ACPI-based processor performance control unavailable\n"));
348 return -ENODEV;
351 result = acpi_processor_get_performance_control(pr);
352 if (result)
353 goto update_bios;
355 result = acpi_processor_get_performance_states(pr);
356 if (result)
357 goto update_bios;
359 return 0;
362 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
363 * the BIOS is older than the CPU and does not know its frequencies
365 update_bios:
366 #ifdef CONFIG_X86
367 if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_PPC", &handle))){
368 if(boot_cpu_has(X86_FEATURE_EST))
369 printk(KERN_WARNING FW_BUG "BIOS needs update for CPU "
370 "frequency support\n");
372 #endif
373 return result;
376 int acpi_processor_notify_smm(struct module *calling_module)
378 acpi_status status;
379 static int is_done = 0;
382 if (!(acpi_processor_ppc_status & PPC_REGISTERED))
383 return -EBUSY;
385 if (!try_module_get(calling_module))
386 return -EINVAL;
388 /* is_done is set to negative if an error occured,
389 * and to postitive if _no_ error occured, but SMM
390 * was already notified. This avoids double notification
391 * which might lead to unexpected results...
393 if (is_done > 0) {
394 module_put(calling_module);
395 return 0;
396 } else if (is_done < 0) {
397 module_put(calling_module);
398 return is_done;
401 is_done = -EIO;
403 /* Can't write pstate_control to smi_command if either value is zero */
404 if ((!acpi_gbl_FADT.smi_command) || (!acpi_gbl_FADT.pstate_control)) {
405 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_control\n"));
406 module_put(calling_module);
407 return 0;
410 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
411 "Writing pstate_control [0x%x] to smi_command [0x%x]\n",
412 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));
414 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
415 (u32) acpi_gbl_FADT.pstate_control, 8);
416 if (ACPI_FAILURE(status)) {
417 ACPI_EXCEPTION((AE_INFO, status,
418 "Failed to write pstate_control [0x%x] to "
419 "smi_command [0x%x]", acpi_gbl_FADT.pstate_control,
420 acpi_gbl_FADT.smi_command));
421 module_put(calling_module);
422 return status;
425 /* Success. If there's no _PPC, we need to fear nothing, so
426 * we can allow the cpufreq driver to be rmmod'ed. */
427 is_done = 1;
429 if (!(acpi_processor_ppc_status & PPC_IN_USE))
430 module_put(calling_module);
432 return 0;
435 EXPORT_SYMBOL(acpi_processor_notify_smm);
437 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
438 /* /proc/acpi/processor/../performance interface (DEPRECATED) */
440 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
441 static struct file_operations acpi_processor_perf_fops = {
442 .owner = THIS_MODULE,
443 .open = acpi_processor_perf_open_fs,
444 .read = seq_read,
445 .llseek = seq_lseek,
446 .release = single_release,
449 static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
451 struct acpi_processor *pr = seq->private;
452 int i;
455 if (!pr)
456 goto end;
458 if (!pr->performance) {
459 seq_puts(seq, "<not supported>\n");
460 goto end;
463 seq_printf(seq, "state count: %d\n"
464 "active state: P%d\n",
465 pr->performance->state_count, pr->performance->state);
467 seq_puts(seq, "states:\n");
468 for (i = 0; i < pr->performance->state_count; i++)
469 seq_printf(seq,
470 " %cP%d: %d MHz, %d mW, %d uS\n",
471 (i == pr->performance->state ? '*' : ' '), i,
472 (u32) pr->performance->states[i].core_frequency,
473 (u32) pr->performance->states[i].power,
474 (u32) pr->performance->states[i].transition_latency);
476 end:
477 return 0;
480 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
482 return single_open(file, acpi_processor_perf_seq_show,
483 PDE(inode)->data);
486 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
488 struct acpi_device *device = NULL;
491 if (acpi_bus_get_device(pr->handle, &device))
492 return;
494 /* add file 'performance' [R/W] */
495 proc_create_data(ACPI_PROCESSOR_FILE_PERFORMANCE, S_IFREG | S_IRUGO,
496 acpi_device_dir(device),
497 &acpi_processor_perf_fops, acpi_driver_data(device));
498 return;
501 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
503 struct acpi_device *device = NULL;
506 if (acpi_bus_get_device(pr->handle, &device))
507 return;
509 /* remove file 'performance' */
510 remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
511 acpi_device_dir(device));
513 return;
516 #else
517 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
519 return;
521 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
523 return;
525 #endif /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
527 static int acpi_processor_get_psd(struct acpi_processor *pr)
529 int result = 0;
530 acpi_status status = AE_OK;
531 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
532 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
533 struct acpi_buffer state = {0, NULL};
534 union acpi_object *psd = NULL;
535 struct acpi_psd_package *pdomain;
537 status = acpi_evaluate_object(pr->handle, "_PSD", NULL, &buffer);
538 if (ACPI_FAILURE(status)) {
539 return -ENODEV;
542 psd = buffer.pointer;
543 if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
544 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
545 result = -EFAULT;
546 goto end;
549 if (psd->package.count != 1) {
550 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
551 result = -EFAULT;
552 goto end;
555 pdomain = &(pr->performance->domain_info);
557 state.length = sizeof(struct acpi_psd_package);
558 state.pointer = pdomain;
560 status = acpi_extract_package(&(psd->package.elements[0]),
561 &format, &state);
562 if (ACPI_FAILURE(status)) {
563 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
564 result = -EFAULT;
565 goto end;
568 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
569 printk(KERN_ERR PREFIX "Unknown _PSD:num_entries\n");
570 result = -EFAULT;
571 goto end;
574 if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
575 printk(KERN_ERR PREFIX "Unknown _PSD:revision\n");
576 result = -EFAULT;
577 goto end;
580 end:
581 kfree(buffer.pointer);
582 return result;
585 int acpi_processor_preregister_performance(
586 struct acpi_processor_performance *performance)
588 int count, count_target;
589 int retval = 0;
590 unsigned int i, j;
591 cpumask_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;
597 mutex_lock(&performance_mutex);
599 retval = 0;
601 /* Call _PSD for all CPUs */
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;
609 if (pr->performance) {
610 retval = -EBUSY;
611 continue;
614 if (!performance || !percpu_ptr(performance, i)) {
615 retval = -EINVAL;
616 continue;
619 pr->performance = percpu_ptr(performance, i);
620 cpu_set(i, pr->performance->shared_cpu_map);
621 if (acpi_processor_get_psd(pr)) {
622 retval = -EINVAL;
623 continue;
626 if (retval)
627 goto err_ret;
630 * Now that we have _PSD data from all CPUs, lets setup P-state
631 * domain info.
633 for_each_possible_cpu(i) {
634 pr = per_cpu(processors, i);
635 if (!pr)
636 continue;
638 /* Basic validity check for domain info */
639 pdomain = &(pr->performance->domain_info);
640 if ((pdomain->revision != ACPI_PSD_REV0_REVISION) ||
641 (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES)) {
642 retval = -EINVAL;
643 goto err_ret;
645 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
646 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
647 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
648 retval = -EINVAL;
649 goto err_ret;
653 cpus_clear(covered_cpus);
654 for_each_possible_cpu(i) {
655 pr = per_cpu(processors, i);
656 if (!pr)
657 continue;
659 if (cpu_isset(i, covered_cpus))
660 continue;
662 pdomain = &(pr->performance->domain_info);
663 cpu_set(i, pr->performance->shared_cpu_map);
664 cpu_set(i, covered_cpus);
665 if (pdomain->num_processors <= 1)
666 continue;
668 /* Validate the Domain info */
669 count_target = pdomain->num_processors;
670 count = 1;
671 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
672 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
673 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
674 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
675 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
676 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
678 for_each_possible_cpu(j) {
679 if (i == j)
680 continue;
682 match_pr = per_cpu(processors, j);
683 if (!match_pr)
684 continue;
686 match_pdomain = &(match_pr->performance->domain_info);
687 if (match_pdomain->domain != pdomain->domain)
688 continue;
690 /* Here i and j are in the same domain */
692 if (match_pdomain->num_processors != count_target) {
693 retval = -EINVAL;
694 goto err_ret;
697 if (pdomain->coord_type != match_pdomain->coord_type) {
698 retval = -EINVAL;
699 goto err_ret;
702 cpu_set(j, covered_cpus);
703 cpu_set(j, pr->performance->shared_cpu_map);
704 count++;
707 for_each_possible_cpu(j) {
708 if (i == j)
709 continue;
711 match_pr = per_cpu(processors, j);
712 if (!match_pr)
713 continue;
715 match_pdomain = &(match_pr->performance->domain_info);
716 if (match_pdomain->domain != pdomain->domain)
717 continue;
719 match_pr->performance->shared_type =
720 pr->performance->shared_type;
721 match_pr->performance->shared_cpu_map =
722 pr->performance->shared_cpu_map;
726 err_ret:
727 for_each_possible_cpu(i) {
728 pr = per_cpu(processors, i);
729 if (!pr || !pr->performance)
730 continue;
732 /* Assume no coordination on any error parsing domain info */
733 if (retval) {
734 cpus_clear(pr->performance->shared_cpu_map);
735 cpu_set(i, pr->performance->shared_cpu_map);
736 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
738 pr->performance = NULL; /* Will be set for real in register */
741 mutex_unlock(&performance_mutex);
742 return retval;
744 EXPORT_SYMBOL(acpi_processor_preregister_performance);
748 acpi_processor_register_performance(struct acpi_processor_performance
749 *performance, unsigned int cpu)
751 struct acpi_processor *pr;
754 if (!(acpi_processor_ppc_status & PPC_REGISTERED))
755 return -EINVAL;
757 mutex_lock(&performance_mutex);
759 pr = per_cpu(processors, cpu);
760 if (!pr) {
761 mutex_unlock(&performance_mutex);
762 return -ENODEV;
765 if (pr->performance) {
766 mutex_unlock(&performance_mutex);
767 return -EBUSY;
770 WARN_ON(!performance);
772 pr->performance = performance;
774 if (acpi_processor_get_performance_info(pr)) {
775 pr->performance = NULL;
776 mutex_unlock(&performance_mutex);
777 return -EIO;
780 acpi_cpufreq_add_file(pr);
782 mutex_unlock(&performance_mutex);
783 return 0;
786 EXPORT_SYMBOL(acpi_processor_register_performance);
788 void
789 acpi_processor_unregister_performance(struct acpi_processor_performance
790 *performance, unsigned int cpu)
792 struct acpi_processor *pr;
795 mutex_lock(&performance_mutex);
797 pr = per_cpu(processors, cpu);
798 if (!pr) {
799 mutex_unlock(&performance_mutex);
800 return;
803 if (pr->performance)
804 kfree(pr->performance->states);
805 pr->performance = NULL;
807 acpi_cpufreq_remove_file(pr);
809 mutex_unlock(&performance_mutex);
811 return;
814 EXPORT_SYMBOL(acpi_processor_unregister_performance);