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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * processor_driver.c - ACPI Processor Driver4 *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 support10 * Copyright (C) 2013, Intel Corporation11 * Rafael J. Wysocki <rafael.j.wysocki@intel.com>12 */13 14#include <linux/kernel.h>15#include <linux/module.h>16#include <linux/init.h>17#include <linux/cpufreq.h>18#include <linux/cpu.h>19#include <linux/cpuidle.h>20#include <linux/slab.h>21#include <linux/acpi.h>22 23#include <acpi/processor.h>24 25#include "internal.h"26 27#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x8028#define ACPI_PROCESSOR_NOTIFY_POWER 0x8129#define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x8230#define ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED 0x8531 32MODULE_AUTHOR("Paul Diefenbaugh");33MODULE_DESCRIPTION("ACPI Processor Driver");34MODULE_LICENSE("GPL");35 36static int acpi_processor_stop(struct device *dev);37 38static const struct acpi_device_id processor_device_ids[] = {39 {ACPI_PROCESSOR_OBJECT_HID, 0},40 {ACPI_PROCESSOR_DEVICE_HID, 0},41 {"", 0},42};43MODULE_DEVICE_TABLE(acpi, processor_device_ids);44 45static struct device_driver acpi_processor_driver = {46 .name = "processor",47 .bus = &cpu_subsys,48 .acpi_match_table = processor_device_ids,49 .remove = acpi_processor_stop,50};51 52static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)53{54 struct acpi_device *device = data;55 struct acpi_processor *pr;56 int saved;57 58 if (device->handle != handle)59 return;60 61 pr = acpi_driver_data(device);62 if (!pr)63 return;64 65 switch (event) {66 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:67 saved = pr->performance_platform_limit;68 acpi_processor_ppc_has_changed(pr, 1);69 if (saved == pr->performance_platform_limit)70 break;71 acpi_bus_generate_netlink_event(device->pnp.device_class,72 dev_name(&device->dev), event,73 pr->performance_platform_limit);74 break;75 case ACPI_PROCESSOR_NOTIFY_POWER:76 acpi_processor_power_state_has_changed(pr);77 acpi_bus_generate_netlink_event(device->pnp.device_class,78 dev_name(&device->dev), event, 0);79 break;80 case ACPI_PROCESSOR_NOTIFY_THROTTLING:81 acpi_processor_tstate_has_changed(pr);82 acpi_bus_generate_netlink_event(device->pnp.device_class,83 dev_name(&device->dev), event, 0);84 break;85 case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED:86 cpufreq_update_limits(pr->id);87 acpi_bus_generate_netlink_event(device->pnp.device_class,88 dev_name(&device->dev), event, 0);89 break;90 default:91 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);92 break;93 }94 95 return;96}97 98static int __acpi_processor_start(struct acpi_device *device);99 100static int acpi_soft_cpu_online(unsigned int cpu)101{102 struct acpi_processor *pr = per_cpu(processors, cpu);103 struct acpi_device *device;104 105 if (!pr)106 return 0;107 108 device = acpi_fetch_acpi_dev(pr->handle);109 if (!device)110 return 0;111 112 /*113 * CPU got physically hotplugged and onlined for the first time:114 * Initialize missing things.115 */116 if (!pr->flags.previously_online) {117 int ret;118 119 ret = __acpi_processor_start(device);120 WARN(ret, "Failed to start CPU: %d\n", pr->id);121 } else {122 /* Normal CPU soft online event. */123 acpi_processor_ppc_has_changed(pr, 0);124 acpi_processor_hotplug(pr);125 acpi_processor_reevaluate_tstate(pr, false);126 acpi_processor_tstate_has_changed(pr);127 }128 return 0;129}130 131static int acpi_soft_cpu_dead(unsigned int cpu)132{133 struct acpi_processor *pr = per_cpu(processors, cpu);134 135 if (!pr || !acpi_fetch_acpi_dev(pr->handle))136 return 0;137 138 acpi_processor_reevaluate_tstate(pr, true);139 return 0;140}141 142#ifdef CONFIG_ACPI_CPU_FREQ_PSS143static void acpi_pss_perf_init(struct acpi_processor *pr)144{145 acpi_processor_ppc_has_changed(pr, 0);146 147 acpi_processor_get_throttling_info(pr);148 149 if (pr->flags.throttling)150 pr->flags.limit = 1;151}152#else153static inline void acpi_pss_perf_init(struct acpi_processor *pr) {}154#endif /* CONFIG_ACPI_CPU_FREQ_PSS */155 156static int __acpi_processor_start(struct acpi_device *device)157{158 struct acpi_processor *pr = acpi_driver_data(device);159 acpi_status status;160 int result = 0;161 162 if (!pr)163 return -ENODEV;164 165 result = acpi_cppc_processor_probe(pr);166 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))167 dev_dbg(&device->dev, "CPPC data invalid or not present\n");168 169 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)170 acpi_processor_power_init(pr);171 172 acpi_pss_perf_init(pr);173 174 result = acpi_processor_thermal_init(pr, device);175 if (result)176 goto err_power_exit;177 178 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,179 acpi_processor_notify, device);180 if (!ACPI_SUCCESS(status)) {181 result = -ENODEV;182 goto err_thermal_exit;183 }184 pr->flags.previously_online = 1;185 186 return 0;187 188err_thermal_exit:189 acpi_processor_thermal_exit(pr, device);190err_power_exit:191 acpi_processor_power_exit(pr);192 return result;193}194 195static int acpi_processor_stop(struct device *dev)196{197 struct acpi_device *device = ACPI_COMPANION(dev);198 struct acpi_processor *pr;199 200 if (!device)201 return 0;202 203 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,204 acpi_processor_notify);205 206 pr = acpi_driver_data(device);207 if (!pr)208 return 0;209 acpi_processor_power_exit(pr);210 211 acpi_cppc_processor_exit(pr);212 213 acpi_processor_thermal_exit(pr, device);214 215 return 0;216}217 218bool acpi_processor_cpufreq_init;219 220static int acpi_processor_notifier(struct notifier_block *nb,221 unsigned long event, void *data)222{223 struct cpufreq_policy *policy = data;224 225 if (event == CPUFREQ_CREATE_POLICY) {226 acpi_thermal_cpufreq_init(policy);227 acpi_processor_ppc_init(policy);228 } else if (event == CPUFREQ_REMOVE_POLICY) {229 acpi_processor_ppc_exit(policy);230 acpi_thermal_cpufreq_exit(policy);231 }232 233 return 0;234}235 236static struct notifier_block acpi_processor_notifier_block = {237 .notifier_call = acpi_processor_notifier,238};239 240void __weak acpi_processor_init_invariance_cppc(void)241{ }242 243/*244 * We keep the driver loaded even when ACPI is not running.245 * This is needed for the powernow-k8 driver, that works even without246 * ACPI, but needs symbols from this driver247 */248static enum cpuhp_state hp_online;249static int __init acpi_processor_driver_init(void)250{251 int result = 0;252 253 if (acpi_disabled)254 return 0;255 256 if (!cpufreq_register_notifier(&acpi_processor_notifier_block,257 CPUFREQ_POLICY_NOTIFIER)) {258 acpi_processor_cpufreq_init = true;259 acpi_processor_ignore_ppc_init();260 }261 262 result = driver_register(&acpi_processor_driver);263 if (result < 0)264 return result;265 266 result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,267 "acpi/cpu-drv:online",268 acpi_soft_cpu_online, NULL);269 if (result < 0)270 goto err;271 hp_online = result;272 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",273 NULL, acpi_soft_cpu_dead);274 275 acpi_processor_throttling_init();276 277 /*278 * Frequency invariance calculations on AMD platforms can't be run until279 * after acpi_cppc_processor_probe() has been called for all online CPUs280 */281 acpi_processor_init_invariance_cppc();282 return 0;283err:284 driver_unregister(&acpi_processor_driver);285 return result;286}287 288static void __exit acpi_processor_driver_exit(void)289{290 if (acpi_disabled)291 return;292 293 if (acpi_processor_cpufreq_init) {294 cpufreq_unregister_notifier(&acpi_processor_notifier_block,295 CPUFREQ_POLICY_NOTIFIER);296 acpi_processor_cpufreq_init = false;297 }298 299 cpuhp_remove_state_nocalls(hp_online);300 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);301 driver_unregister(&acpi_processor_driver);302}303 304module_init(acpi_processor_driver_init);305module_exit(acpi_processor_driver_exit);306 307MODULE_ALIAS("processor");308