Contributors: 37
Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
Len Brown |
1173 |
37.27% |
6 |
10.17% |
Venkatesh Pallipadi |
731 |
23.23% |
2 |
3.39% |
Rafael J. Wysocki |
226 |
7.18% |
9 |
15.25% |
Thomas Renninger |
166 |
5.27% |
6 |
10.17% |
Matthew Garrett |
163 |
5.18% |
1 |
1.69% |
Viresh Kumar |
141 |
4.48% |
1 |
1.69% |
Marco Aurelio da Costa |
93 |
2.96% |
1 |
1.69% |
Yakui Zhao |
74 |
2.35% |
1 |
1.69% |
Stanislaw Gruszka |
64 |
2.03% |
1 |
1.69% |
Patrick Mochel |
48 |
1.53% |
1 |
1.69% |
Hanjun Guo |
45 |
1.43% |
1 |
1.69% |
Rusty Russell |
33 |
1.05% |
2 |
3.39% |
Mike Travis |
28 |
0.89% |
1 |
1.69% |
Joao Martins |
25 |
0.79% |
1 |
1.69% |
Jiang Liu |
18 |
0.57% |
2 |
3.39% |
Arjan van de Ven |
18 |
0.57% |
1 |
1.69% |
Darrick J. Wong |
15 |
0.48% |
1 |
1.69% |
Stefan Bader |
14 |
0.44% |
1 |
1.69% |
Andrew Morton |
12 |
0.38% |
1 |
1.69% |
Miao Xie |
10 |
0.32% |
1 |
1.69% |
Kees Cook |
7 |
0.22% |
1 |
1.69% |
Fenghua Yu |
6 |
0.19% |
1 |
1.69% |
Lv Zheng |
6 |
0.19% |
1 |
1.69% |
Kamezawa Hiroyuki |
5 |
0.16% |
1 |
1.69% |
Chen Yu |
5 |
0.16% |
1 |
1.69% |
Konrad Rzeszutek Wilk |
5 |
0.16% |
1 |
1.69% |
Tejun Heo |
4 |
0.13% |
2 |
3.39% |
Maximilian Luz |
2 |
0.06% |
1 |
1.69% |
Thomas Gleixner |
2 |
0.06% |
1 |
1.69% |
Matthew Wilcox |
1 |
0.03% |
1 |
1.69% |
Li Zefan |
1 |
0.03% |
1 |
1.69% |
Tom Saeger |
1 |
0.03% |
1 |
1.69% |
Ionela Voinescu |
1 |
0.03% |
1 |
1.69% |
Lucas De Marchi |
1 |
0.03% |
1 |
1.69% |
Dominik Brodowski |
1 |
0.03% |
1 |
1.69% |
Milan Broz |
1 |
0.03% |
1 |
1.69% |
Alexey Y. Starikovskiy |
1 |
0.03% |
1 |
1.69% |
Total |
3147 |
|
59 |
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* - Added processor hotplug support
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <acpi/processor.h>
#ifdef CONFIG_X86
#include <asm/cpufeature.h>
#endif
#define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
static DEFINE_MUTEX(performance_mutex);
/*
* _PPC support is implemented as a CPUfreq policy notifier:
* This means each time a CPUfreq driver registered also with
* the ACPI core is asked to change the speed policy, the maximum
* value is adjusted so that it is within the platform limit.
*
* Also, when a new platform limit value is detected, the CPUfreq
* policy is adjusted accordingly.
*/
/* ignore_ppc:
* -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
* ignore _PPC
* 0 -> cpufreq low level drivers initialized -> consider _PPC values
* 1 -> ignore _PPC totally -> forced by user through boot param
*/
static int ignore_ppc = -1;
module_param(ignore_ppc, int, 0644);
MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
"limited by BIOS, this should help");
static bool acpi_processor_ppc_in_use;
static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
{
acpi_status status = 0;
unsigned long long ppc = 0;
int ret;
if (!pr)
return -EINVAL;
/*
* _PPC indicates the maximum state currently supported by the platform
* (e.g. 0 = states 0..n; 1 = states 1..n; etc.
*/
status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
if (status != AE_NOT_FOUND) {
acpi_processor_ppc_in_use = true;
if (ACPI_FAILURE(status)) {
acpi_evaluation_failure_warn(pr->handle, "_PPC", status);
return -ENODEV;
}
}
pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
(int)ppc, ppc ? "" : "not");
pr->performance_platform_limit = (int)ppc;
if (ppc >= pr->performance->state_count ||
unlikely(!freq_qos_request_active(&pr->perflib_req)))
return 0;
ret = freq_qos_update_request(&pr->perflib_req,
pr->performance->states[ppc].core_frequency * 1000);
if (ret < 0) {
pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n",
pr->id, ret);
}
return 0;
}
#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
/*
* acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status
* @handle: ACPI processor handle
* @status: the status code of _PPC evaluation
* 0: success. OSPM is now using the performance state specified.
* 1: failure. OSPM has not changed the number of P-states in use
*/
static void acpi_processor_ppc_ost(acpi_handle handle, int status)
{
if (acpi_has_method(handle, "_OST"))
acpi_evaluate_ost(handle, ACPI_PROCESSOR_NOTIFY_PERFORMANCE,
status, NULL);
}
void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
{
int ret;
if (ignore_ppc || !pr->performance) {
/*
* Only when it is notification event, the _OST object
* will be evaluated. Otherwise it is skipped.
*/
if (event_flag)
acpi_processor_ppc_ost(pr->handle, 1);
return;
}
ret = acpi_processor_get_platform_limit(pr);
/*
* Only when it is notification event, the _OST object
* will be evaluated. Otherwise it is skipped.
*/
if (event_flag) {
if (ret < 0)
acpi_processor_ppc_ost(pr->handle, 1);
else
acpi_processor_ppc_ost(pr->handle, 0);
}
if (ret >= 0)
cpufreq_update_limits(pr->id);
}
int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
{
struct acpi_processor *pr;
pr = per_cpu(processors, cpu);
if (!pr || !pr->performance || !pr->performance->state_count)
return -ENODEV;
*limit = pr->performance->states[pr->performance_platform_limit].
core_frequency * 1000;
return 0;
}
EXPORT_SYMBOL(acpi_processor_get_bios_limit);
void acpi_processor_ignore_ppc_init(void)
{
if (ignore_ppc < 0)
ignore_ppc = 0;
}
void acpi_processor_ppc_init(struct cpufreq_policy *policy)
{
unsigned int cpu;
for_each_cpu(cpu, policy->related_cpus) {
struct acpi_processor *pr = per_cpu(processors, cpu);
int ret;
if (!pr)
continue;
ret = freq_qos_add_request(&policy->constraints,
&pr->perflib_req,
FREQ_QOS_MAX, INT_MAX);
if (ret < 0)
pr_err("Failed to add freq constraint for CPU%d (%d)\n",
cpu, ret);
}
}
void acpi_processor_ppc_exit(struct cpufreq_policy *policy)
{
unsigned int cpu;
for_each_cpu(cpu, policy->related_cpus) {
struct acpi_processor *pr = per_cpu(processors, cpu);
if (pr)
freq_qos_remove_request(&pr->perflib_req);
}
}
static int acpi_processor_get_performance_control(struct acpi_processor *pr)
{
int result = 0;
acpi_status status = 0;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *pct = NULL;
union acpi_object obj = { 0 };
status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
if (ACPI_FAILURE(status)) {
acpi_evaluation_failure_warn(pr->handle, "_PCT", status);
return -ENODEV;
}
pct = (union acpi_object *)buffer.pointer;
if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
|| (pct->package.count != 2)) {
pr_err("Invalid _PCT data\n");
result = -EFAULT;
goto end;
}
/*
* control_register
*/
obj = pct->package.elements[0];
if ((obj.type != ACPI_TYPE_BUFFER)
|| (obj.buffer.length < sizeof(struct acpi_pct_register))
|| (obj.buffer.pointer == NULL)) {
pr_err("Invalid _PCT data (control_register)\n");
result = -EFAULT;
goto end;
}
memcpy(&pr->performance->control_register, obj.buffer.pointer,
sizeof(struct acpi_pct_register));
/*
* status_register
*/
obj = pct->package.elements[1];
if ((obj.type != ACPI_TYPE_BUFFER)
|| (obj.buffer.length < sizeof(struct acpi_pct_register))
|| (obj.buffer.pointer == NULL)) {
pr_err("Invalid _PCT data (status_register)\n");
result = -EFAULT;
goto end;
}
memcpy(&pr->performance->status_register, obj.buffer.pointer,
sizeof(struct acpi_pct_register));
end:
kfree(buffer.pointer);
return result;
}
#ifdef CONFIG_X86
/*
* Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding
* in their ACPI data. Calculate the real values and fix up the _PSS data.
*/
static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
{
u32 hi, lo, fid, did;
int index = px->control & 0x00000007;
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
return;
if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
|| boot_cpu_data.x86 == 0x11) {
rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
/*
* MSR C001_0064+:
* Bit 63: PstateEn. Read-write. If set, the P-state is valid.
*/
if (!(hi & BIT(31)))
return;
fid = lo & 0x3f;
did = (lo >> 6) & 7;
if (boot_cpu_data.x86 == 0x10)
px->core_frequency = (100 * (fid + 0x10)) >> did;
else
px->core_frequency = (100 * (fid + 8)) >> did;
}
}
#else
static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {};
#endif
static int acpi_processor_get_performance_states(struct acpi_processor *pr)
{
int result = 0;
acpi_status status = AE_OK;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
struct acpi_buffer state = { 0, NULL };
union acpi_object *pss = NULL;
int i;
int last_invalid = -1;
status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
if (ACPI_FAILURE(status)) {
acpi_evaluation_failure_warn(pr->handle, "_PSS", status);
return -ENODEV;
}
pss = buffer.pointer;
if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
pr_err("Invalid _PSS data\n");
result = -EFAULT;
goto end;
}
acpi_handle_debug(pr->handle, "Found %d performance states\n",
pss->package.count);
pr->performance->state_count = pss->package.count;
pr->performance->states =
kmalloc_array(pss->package.count,
sizeof(struct acpi_processor_px),
GFP_KERNEL);
if (!pr->performance->states) {
result = -ENOMEM;
goto end;
}
for (i = 0; i < pr->performance->state_count; i++) {
struct acpi_processor_px *px = &(pr->performance->states[i]);
state.length = sizeof(struct acpi_processor_px);
state.pointer = px;
acpi_handle_debug(pr->handle, "Extracting state %d\n", i);
status = acpi_extract_package(&(pss->package.elements[i]),
&format, &state);
if (ACPI_FAILURE(status)) {
acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n",
acpi_format_exception(status));
result = -EFAULT;
kfree(pr->performance->states);
goto end;
}
amd_fixup_frequency(px, i);
acpi_handle_debug(pr->handle,
"State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
i,
(u32) px->core_frequency,
(u32) px->power,
(u32) px->transition_latency,
(u32) px->bus_master_latency,
(u32) px->control, (u32) px->status);
/*
* Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq
*/
if (!px->core_frequency ||
((u32)(px->core_frequency * 1000) !=
(px->core_frequency * 1000))) {
pr_err(FW_BUG
"Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n",
pr->id, px->core_frequency);
if (last_invalid == -1)
last_invalid = i;
} else {
if (last_invalid != -1) {
/*
* Copy this valid entry over last_invalid entry
*/
memcpy(&(pr->performance->states[last_invalid]),
px, sizeof(struct acpi_processor_px));
++last_invalid;
}
}
}
if (last_invalid == 0) {
pr_err(FW_BUG
"No valid BIOS _PSS frequency found for processor %d\n", pr->id);
result = -EFAULT;
kfree(pr->performance->states);
pr->performance->states = NULL;
}
if (last_invalid > 0)
pr->performance->state_count = last_invalid;
end:
kfree(buffer.pointer);
return result;
}
int acpi_processor_get_performance_info(struct acpi_processor *pr)
{
int result = 0;
if (!pr || !pr->performance || !pr->handle)
return -EINVAL;
if (!acpi_has_method(pr->handle, "_PCT")) {
acpi_handle_debug(pr->handle,
"ACPI-based processor performance control unavailable\n");
return -ENODEV;
}
result = acpi_processor_get_performance_control(pr);
if (result)
goto update_bios;
result = acpi_processor_get_performance_states(pr);
if (result)
goto update_bios;
/* We need to call _PPC once when cpufreq starts */
if (ignore_ppc != 1)
result = acpi_processor_get_platform_limit(pr);
return result;
/*
* Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
* the BIOS is older than the CPU and does not know its frequencies
*/
update_bios:
#ifdef CONFIG_X86
if (acpi_has_method(pr->handle, "_PPC")) {
if(boot_cpu_has(X86_FEATURE_EST))
pr_warn(FW_BUG "BIOS needs update for CPU "
"frequency support\n");
}
#endif
return result;
}
EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info);
int acpi_processor_pstate_control(void)
{
acpi_status status;
if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control)
return 0;
pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n",
acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command);
status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
(u32)acpi_gbl_FADT.pstate_control, 8);
if (ACPI_SUCCESS(status))
return 1;
pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n",
acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command,
acpi_format_exception(status));
return -EIO;
}
int acpi_processor_notify_smm(struct module *calling_module)
{
static int is_done;
int result;
if (!acpi_processor_cpufreq_init)
return -EBUSY;
if (!try_module_get(calling_module))
return -EINVAL;
/* is_done is set to negative if an error occurred,
* and to postitive if _no_ error occurred, but SMM
* was already notified. This avoids double notification
* which might lead to unexpected results...
*/
if (is_done > 0) {
module_put(calling_module);
return 0;
} else if (is_done < 0) {
module_put(calling_module);
return is_done;
}
is_done = -EIO;
result = acpi_processor_pstate_control();
if (!result) {
pr_debug("No SMI port or pstate_control\n");
module_put(calling_module);
return 0;
}
if (result < 0) {
module_put(calling_module);
return result;
}
/* Success. If there's no _PPC, we need to fear nothing, so
* we can allow the cpufreq driver to be rmmod'ed. */
is_done = 1;
if (!acpi_processor_ppc_in_use)
module_put(calling_module);
return 0;
}
EXPORT_SYMBOL(acpi_processor_notify_smm);
int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
{
int result = 0;
acpi_status status = AE_OK;
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
struct acpi_buffer state = {0, NULL};
union acpi_object *psd = NULL;
status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer);
if (ACPI_FAILURE(status)) {
return -ENODEV;
}
psd = buffer.pointer;
if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
pr_err("Invalid _PSD data\n");
result = -EFAULT;
goto end;
}
if (psd->package.count != 1) {
pr_err("Invalid _PSD data\n");
result = -EFAULT;
goto end;
}
state.length = sizeof(struct acpi_psd_package);
state.pointer = pdomain;
status = acpi_extract_package(&(psd->package.elements[0]),
&format, &state);
if (ACPI_FAILURE(status)) {
pr_err("Invalid _PSD data\n");
result = -EFAULT;
goto end;
}
if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
pr_err("Unknown _PSD:num_entries\n");
result = -EFAULT;
goto end;
}
if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
pr_err("Unknown _PSD:revision\n");
result = -EFAULT;
goto end;
}
if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
pr_err("Invalid _PSD:coord_type\n");
result = -EFAULT;
goto end;
}
end:
kfree(buffer.pointer);
return result;
}
EXPORT_SYMBOL(acpi_processor_get_psd);
int acpi_processor_preregister_performance(
struct acpi_processor_performance __percpu *performance)
{
int count_target;
int retval = 0;
unsigned int i, j;
cpumask_var_t covered_cpus;
struct acpi_processor *pr;
struct acpi_psd_package *pdomain;
struct acpi_processor *match_pr;
struct acpi_psd_package *match_pdomain;
if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
return -ENOMEM;
mutex_lock(&performance_mutex);
/*
* Check if another driver has already registered, and abort before
* changing pr->performance if it has. Check input data as well.
*/
for_each_possible_cpu(i) {
pr = per_cpu(processors, i);
if (!pr) {
/* Look only at processors in ACPI namespace */
continue;
}
if (pr->performance) {
retval = -EBUSY;
goto err_out;
}
if (!performance || !per_cpu_ptr(performance, i)) {
retval = -EINVAL;
goto err_out;
}
}
/* Call _PSD for all CPUs */
for_each_possible_cpu(i) {
pr = per_cpu(processors, i);
if (!pr)
continue;
pr->performance = per_cpu_ptr(performance, i);
pdomain = &(pr->performance->domain_info);
if (acpi_processor_get_psd(pr->handle, pdomain)) {
retval = -EINVAL;
continue;
}
}
if (retval)
goto err_ret;
/*
* Now that we have _PSD data from all CPUs, lets setup P-state
* domain info.
*/
for_each_possible_cpu(i) {
pr = per_cpu(processors, i);
if (!pr)
continue;
if (cpumask_test_cpu(i, covered_cpus))
continue;
pdomain = &(pr->performance->domain_info);
cpumask_set_cpu(i, pr->performance->shared_cpu_map);
cpumask_set_cpu(i, covered_cpus);
if (pdomain->num_processors <= 1)
continue;
/* Validate the Domain info */
count_target = pdomain->num_processors;
if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
for_each_possible_cpu(j) {
if (i == j)
continue;
match_pr = per_cpu(processors, j);
if (!match_pr)
continue;
match_pdomain = &(match_pr->performance->domain_info);
if (match_pdomain->domain != pdomain->domain)
continue;
/* Here i and j are in the same domain */
if (match_pdomain->num_processors != count_target) {
retval = -EINVAL;
goto err_ret;
}
if (pdomain->coord_type != match_pdomain->coord_type) {
retval = -EINVAL;
goto err_ret;
}
cpumask_set_cpu(j, covered_cpus);
cpumask_set_cpu(j, pr->performance->shared_cpu_map);
}
for_each_possible_cpu(j) {
if (i == j)
continue;
match_pr = per_cpu(processors, j);
if (!match_pr)
continue;
match_pdomain = &(match_pr->performance->domain_info);
if (match_pdomain->domain != pdomain->domain)
continue;
match_pr->performance->shared_type =
pr->performance->shared_type;
cpumask_copy(match_pr->performance->shared_cpu_map,
pr->performance->shared_cpu_map);
}
}
err_ret:
for_each_possible_cpu(i) {
pr = per_cpu(processors, i);
if (!pr || !pr->performance)
continue;
/* Assume no coordination on any error parsing domain info */
if (retval) {
cpumask_clear(pr->performance->shared_cpu_map);
cpumask_set_cpu(i, pr->performance->shared_cpu_map);
pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE;
}
pr->performance = NULL; /* Will be set for real in register */
}
err_out:
mutex_unlock(&performance_mutex);
free_cpumask_var(covered_cpus);
return retval;
}
EXPORT_SYMBOL(acpi_processor_preregister_performance);
int
acpi_processor_register_performance(struct acpi_processor_performance
*performance, unsigned int cpu)
{
struct acpi_processor *pr;
if (!acpi_processor_cpufreq_init)
return -EINVAL;
mutex_lock(&performance_mutex);
pr = per_cpu(processors, cpu);
if (!pr) {
mutex_unlock(&performance_mutex);
return -ENODEV;
}
if (pr->performance) {
mutex_unlock(&performance_mutex);
return -EBUSY;
}
WARN_ON(!performance);
pr->performance = performance;
if (acpi_processor_get_performance_info(pr)) {
pr->performance = NULL;
mutex_unlock(&performance_mutex);
return -EIO;
}
mutex_unlock(&performance_mutex);
return 0;
}
EXPORT_SYMBOL(acpi_processor_register_performance);
void acpi_processor_unregister_performance(unsigned int cpu)
{
struct acpi_processor *pr;
mutex_lock(&performance_mutex);
pr = per_cpu(processors, cpu);
if (!pr) {
mutex_unlock(&performance_mutex);
return;
}
if (pr->performance)
kfree(pr->performance->states);
pr->performance = NULL;
mutex_unlock(&performance_mutex);
return;
}
EXPORT_SYMBOL(acpi_processor_unregister_performance);