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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/acpi/processor_perflib.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/acpi/processor_perflib.c')
-rw-r--r-- | drivers/acpi/processor_perflib.c | 806 |
1 files changed, 806 insertions, 0 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c new file mode 100644 index 000000000..fc42d649c --- /dev/null +++ b/drivers/acpi/processor_perflib.c @@ -0,0 +1,806 @@ +// 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 + */ + +#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 PREFIX "ACPI: " + +#define ACPI_PROCESSOR_CLASS "processor" +#define ACPI_PROCESSOR_FILE_PERFORMANCE "performance" +#define _COMPONENT ACPI_PROCESSOR_COMPONENT +ACPI_MODULE_NAME("processor_perflib"); + +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; + s32 qos_value; + int index; + 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) && status != AE_NOT_FOUND) { + ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PPC")); + return -ENODEV; + } + + index = ppc; + + if (pr->performance_platform_limit == index || + ppc >= pr->performance->state_count) + return 0; + + pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id, + index, index ? "is" : "is not"); + + pr->performance_platform_limit = index; + + if (unlikely(!freq_qos_request_active(&pr->perflib_req))) + return 0; + + /* + * If _PPC returns 0, it means that all of the available states can be + * used ("no limit"). + */ + if (index == 0) + qos_value = FREQ_QOS_MAX_DEFAULT_VALUE; + else + qos_value = pr->performance->states[index].core_frequency * 1000; + + ret = freq_qos_update_request(&pr->perflib_req, qos_value); + 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 specificed. + * 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; + + /* + * Reset performance_platform_limit in case there is a stale + * value in it, so as to make it match the "no limit" QoS value + * below. + */ + pr->performance_platform_limit = 0; + + ret = freq_qos_add_request(&policy->constraints, + &pr->perflib_req, FREQ_QOS_MAX, + FREQ_QOS_MAX_DEFAULT_VALUE); + 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_EXCEPTION((AE_INFO, status, "Evaluating _PCT")); + return -ENODEV; + } + + pct = (union acpi_object *)buffer.pointer; + if (!pct || (pct->type != ACPI_TYPE_PACKAGE) + || (pct->package.count != 2)) { + printk(KERN_ERR PREFIX "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)) { + printk(KERN_ERR PREFIX "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)) { + printk(KERN_ERR PREFIX "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_EXCEPTION((AE_INFO, status, "Evaluating _PSS")); + return -ENODEV; + } + + pss = buffer.pointer; + if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) { + printk(KERN_ERR PREFIX "Invalid _PSS data\n"); + result = -EFAULT; + goto end; + } + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "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_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i)); + + status = acpi_extract_package(&(pss->package.elements[i]), + &format, &state); + if (ACPI_FAILURE(status)) { + ACPI_EXCEPTION((AE_INFO, status, "Invalid _PSS data")); + result = -EFAULT; + kfree(pr->performance->states); + goto end; + } + + amd_fixup_frequency(px, i); + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "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))) { + printk(KERN_ERR FW_BUG PREFIX + "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) { + printk(KERN_ERR FW_BUG PREFIX + "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_DEBUG_PRINT((ACPI_DB_INFO, + "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)) + printk(KERN_WARNING 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; + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "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; + + ACPI_EXCEPTION((AE_INFO, status, + "Failed to write pstate_control [0x%x] to smi_command [0x%x]", + acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command)); + return -EIO; +} + +int acpi_processor_notify_smm(struct module *calling_module) +{ + static int is_done = 0; + 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) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "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)) { + printk(KERN_ERR PREFIX "Invalid _PSD data\n"); + result = -EFAULT; + goto end; + } + + if (psd->package.count != 1) { + printk(KERN_ERR PREFIX "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)) { + printk(KERN_ERR PREFIX "Invalid _PSD data\n"); + result = -EFAULT; + goto end; + } + + if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { + printk(KERN_ERR PREFIX "Unknown _PSD:num_entries\n"); + result = -EFAULT; + goto end; + } + + if (pdomain->revision != ACPI_PSD_REV0_REVISION) { + printk(KERN_ERR PREFIX "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) { + printk(KERN_ERR PREFIX "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); + cpumask_set_cpu(i, pr->performance->shared_cpu_map); + 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_ALL; + } + 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); |