1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * processor_driver.c - ACPI Processor Driver 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 * Copyright (C) 2013, Intel Corporation 11 * 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 0x80 28 #define ACPI_PROCESSOR_NOTIFY_POWER 0x81 29 #define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82 30 #define ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED 0x85 31 32 MODULE_AUTHOR("Paul Diefenbaugh"); 33 MODULE_DESCRIPTION("ACPI Processor Driver"); 34 MODULE_LICENSE("GPL"); 35 36 static int acpi_processor_start(struct device *dev); 37 static int acpi_processor_stop(struct device *dev); 38 39 static const struct acpi_device_id processor_device_ids[] = { 40 {ACPI_PROCESSOR_OBJECT_HID, 0}, 41 {ACPI_PROCESSOR_DEVICE_HID, 0}, 42 {"", 0}, 43 }; 44 MODULE_DEVICE_TABLE(acpi, processor_device_ids); 45 46 static struct device_driver acpi_processor_driver = { 47 .name = "processor", 48 .bus = &cpu_subsys, 49 .acpi_match_table = processor_device_ids, 50 .probe = acpi_processor_start, 51 .remove = acpi_processor_stop, 52 }; 53 54 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data) 55 { 56 struct acpi_device *device = data; 57 struct acpi_processor *pr; 58 int saved; 59 60 if (device->handle != handle) 61 return; 62 63 pr = acpi_driver_data(device); 64 if (!pr) 65 return; 66 67 switch (event) { 68 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE: 69 saved = pr->performance_platform_limit; 70 acpi_processor_ppc_has_changed(pr, 1); 71 if (saved == pr->performance_platform_limit) 72 break; 73 acpi_bus_generate_netlink_event(device->pnp.device_class, 74 dev_name(&device->dev), event, 75 pr->performance_platform_limit); 76 break; 77 case ACPI_PROCESSOR_NOTIFY_POWER: 78 acpi_processor_power_state_has_changed(pr); 79 acpi_bus_generate_netlink_event(device->pnp.device_class, 80 dev_name(&device->dev), event, 0); 81 break; 82 case ACPI_PROCESSOR_NOTIFY_THROTTLING: 83 acpi_processor_tstate_has_changed(pr); 84 acpi_bus_generate_netlink_event(device->pnp.device_class, 85 dev_name(&device->dev), event, 0); 86 break; 87 case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED: 88 cpufreq_update_limits(pr->id); 89 acpi_bus_generate_netlink_event(device->pnp.device_class, 90 dev_name(&device->dev), event, 0); 91 break; 92 default: 93 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event); 94 break; 95 } 96 97 return; 98 } 99 100 static int __acpi_processor_start(struct acpi_device *device); 101 102 static int acpi_soft_cpu_online(unsigned int cpu) 103 { 104 struct acpi_processor *pr = per_cpu(processors, cpu); 105 struct acpi_device *device; 106 107 if (!pr) 108 return 0; 109 110 device = acpi_fetch_acpi_dev(pr->handle); 111 if (!device) 112 return 0; 113 114 /* 115 * CPU got physically hotplugged and onlined for the first time: 116 * Initialize missing things. 117 */ 118 if (pr->flags.need_hotplug_init) { 119 int ret; 120 121 pr_info("Will online and init hotplugged CPU: %d\n", 122 pr->id); 123 pr->flags.need_hotplug_init = 0; 124 ret = __acpi_processor_start(device); 125 WARN(ret, "Failed to start CPU: %d\n", pr->id); 126 } else { 127 /* Normal CPU soft online event. */ 128 acpi_processor_ppc_has_changed(pr, 0); 129 acpi_processor_hotplug(pr); 130 acpi_processor_reevaluate_tstate(pr, false); 131 acpi_processor_tstate_has_changed(pr); 132 } 133 return 0; 134 } 135 136 static int acpi_soft_cpu_dead(unsigned int cpu) 137 { 138 struct acpi_processor *pr = per_cpu(processors, cpu); 139 140 if (!pr || !acpi_fetch_acpi_dev(pr->handle)) 141 return 0; 142 143 acpi_processor_reevaluate_tstate(pr, true); 144 return 0; 145 } 146 147 #ifdef CONFIG_ACPI_CPU_FREQ_PSS 148 static void acpi_pss_perf_init(struct acpi_processor *pr) 149 { 150 acpi_processor_ppc_has_changed(pr, 0); 151 152 acpi_processor_get_throttling_info(pr); 153 154 if (pr->flags.throttling) 155 pr->flags.limit = 1; 156 } 157 #else 158 static inline void acpi_pss_perf_init(struct acpi_processor *pr) {} 159 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */ 160 161 static int __acpi_processor_start(struct acpi_device *device) 162 { 163 struct acpi_processor *pr = acpi_driver_data(device); 164 acpi_status status; 165 int result = 0; 166 167 if (!pr) 168 return -ENODEV; 169 170 if (pr->flags.need_hotplug_init) 171 return 0; 172 173 result = acpi_cppc_processor_probe(pr); 174 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS)) 175 dev_dbg(&device->dev, "CPPC data invalid or not present\n"); 176 177 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 178 acpi_processor_power_init(pr); 179 180 acpi_pss_perf_init(pr); 181 182 result = acpi_processor_thermal_init(pr, device); 183 if (result) 184 goto err_power_exit; 185 186 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 187 acpi_processor_notify, device); 188 if (ACPI_SUCCESS(status)) 189 return 0; 190 191 result = -ENODEV; 192 acpi_processor_thermal_exit(pr, device); 193 194 err_power_exit: 195 acpi_processor_power_exit(pr); 196 return result; 197 } 198 199 static int acpi_processor_start(struct device *dev) 200 { 201 struct acpi_device *device = ACPI_COMPANION(dev); 202 int ret; 203 204 if (!device) 205 return -ENODEV; 206 207 /* Protect against concurrent CPU hotplug operations */ 208 cpu_hotplug_disable(); 209 ret = __acpi_processor_start(device); 210 cpu_hotplug_enable(); 211 return ret; 212 } 213 214 static int acpi_processor_stop(struct device *dev) 215 { 216 struct acpi_device *device = ACPI_COMPANION(dev); 217 struct acpi_processor *pr; 218 219 if (!device) 220 return 0; 221 222 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 223 acpi_processor_notify); 224 225 pr = acpi_driver_data(device); 226 if (!pr) 227 return 0; 228 acpi_processor_power_exit(pr); 229 230 acpi_cppc_processor_exit(pr); 231 232 acpi_processor_thermal_exit(pr, device); 233 234 return 0; 235 } 236 237 bool acpi_processor_cpufreq_init; 238 239 static int acpi_processor_notifier(struct notifier_block *nb, 240 unsigned long event, void *data) 241 { 242 struct cpufreq_policy *policy = data; 243 244 if (event == CPUFREQ_CREATE_POLICY) { 245 acpi_thermal_cpufreq_init(policy); 246 acpi_processor_ppc_init(policy); 247 } else if (event == CPUFREQ_REMOVE_POLICY) { 248 acpi_processor_ppc_exit(policy); 249 acpi_thermal_cpufreq_exit(policy); 250 } 251 252 return 0; 253 } 254 255 static struct notifier_block acpi_processor_notifier_block = { 256 .notifier_call = acpi_processor_notifier, 257 }; 258 259 /* 260 * We keep the driver loaded even when ACPI is not running. 261 * This is needed for the powernow-k8 driver, that works even without 262 * ACPI, but needs symbols from this driver 263 */ 264 static enum cpuhp_state hp_online; 265 static int __init acpi_processor_driver_init(void) 266 { 267 int result = 0; 268 269 if (acpi_disabled) 270 return 0; 271 272 if (!cpufreq_register_notifier(&acpi_processor_notifier_block, 273 CPUFREQ_POLICY_NOTIFIER)) { 274 acpi_processor_cpufreq_init = true; 275 acpi_processor_ignore_ppc_init(); 276 } 277 278 result = driver_register(&acpi_processor_driver); 279 if (result < 0) 280 return result; 281 282 result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, 283 "acpi/cpu-drv:online", 284 acpi_soft_cpu_online, NULL); 285 if (result < 0) 286 goto err; 287 hp_online = result; 288 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead", 289 NULL, acpi_soft_cpu_dead); 290 291 acpi_processor_throttling_init(); 292 return 0; 293 err: 294 driver_unregister(&acpi_processor_driver); 295 return result; 296 } 297 298 static void __exit acpi_processor_driver_exit(void) 299 { 300 if (acpi_disabled) 301 return; 302 303 if (acpi_processor_cpufreq_init) { 304 cpufreq_unregister_notifier(&acpi_processor_notifier_block, 305 CPUFREQ_POLICY_NOTIFIER); 306 acpi_processor_cpufreq_init = false; 307 } 308 309 cpuhp_remove_state_nocalls(hp_online); 310 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD); 311 driver_unregister(&acpi_processor_driver); 312 } 313 314 module_init(acpi_processor_driver_init); 315 module_exit(acpi_processor_driver_exit); 316 317 MODULE_ALIAS("processor"); 318