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 31 MODULE_AUTHOR("Paul Diefenbaugh"); 32 MODULE_DESCRIPTION("ACPI Processor Driver"); 33 MODULE_LICENSE("GPL"); 34 35 static int acpi_processor_start(struct device *dev); 36 static int acpi_processor_stop(struct device *dev); 37 38 static const struct acpi_device_id processor_device_ids[] = { 39 {ACPI_PROCESSOR_OBJECT_HID, 0}, 40 {ACPI_PROCESSOR_DEVICE_HID, 0}, 41 {"", 0}, 42 }; 43 MODULE_DEVICE_TABLE(acpi, processor_device_ids); 44 45 static struct device_driver acpi_processor_driver = { 46 .name = "processor", 47 .bus = &cpu_subsys, 48 .acpi_match_table = processor_device_ids, 49 .probe = acpi_processor_start, 50 .remove = acpi_processor_stop, 51 }; 52 53 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data) 54 { 55 struct acpi_device *device = data; 56 struct acpi_processor *pr; 57 int saved; 58 59 if (device->handle != handle) 60 return; 61 62 pr = acpi_driver_data(device); 63 if (!pr) 64 return; 65 66 switch (event) { 67 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE: 68 saved = pr->performance_platform_limit; 69 acpi_processor_ppc_has_changed(pr, 1); 70 if (saved == pr->performance_platform_limit) 71 break; 72 acpi_bus_generate_netlink_event(device->pnp.device_class, 73 dev_name(&device->dev), event, 74 pr->performance_platform_limit); 75 break; 76 case ACPI_PROCESSOR_NOTIFY_POWER: 77 acpi_processor_power_state_has_changed(pr); 78 acpi_bus_generate_netlink_event(device->pnp.device_class, 79 dev_name(&device->dev), event, 0); 80 break; 81 case ACPI_PROCESSOR_NOTIFY_THROTTLING: 82 acpi_processor_tstate_has_changed(pr); 83 acpi_bus_generate_netlink_event(device->pnp.device_class, 84 dev_name(&device->dev), event, 0); 85 break; 86 default: 87 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event); 88 break; 89 } 90 91 return; 92 } 93 94 static int __acpi_processor_start(struct acpi_device *device); 95 96 static int acpi_soft_cpu_online(unsigned int cpu) 97 { 98 struct acpi_processor *pr = per_cpu(processors, cpu); 99 struct acpi_device *device; 100 101 if (!pr) 102 return 0; 103 104 device = acpi_fetch_acpi_dev(pr->handle); 105 if (!device) 106 return 0; 107 108 /* 109 * CPU got physically hotplugged and onlined for the first time: 110 * Initialize missing things. 111 */ 112 if (pr->flags.need_hotplug_init) { 113 int ret; 114 115 pr_info("Will online and init hotplugged CPU: %d\n", 116 pr->id); 117 pr->flags.need_hotplug_init = 0; 118 ret = __acpi_processor_start(device); 119 WARN(ret, "Failed to start CPU: %d\n", pr->id); 120 } else { 121 /* Normal CPU soft online event. */ 122 acpi_processor_ppc_has_changed(pr, 0); 123 acpi_processor_hotplug(pr); 124 acpi_processor_reevaluate_tstate(pr, false); 125 acpi_processor_tstate_has_changed(pr); 126 } 127 return 0; 128 } 129 130 static int acpi_soft_cpu_dead(unsigned int cpu) 131 { 132 struct acpi_processor *pr = per_cpu(processors, cpu); 133 134 if (!pr || !acpi_fetch_acpi_dev(pr->handle)) 135 return 0; 136 137 acpi_processor_reevaluate_tstate(pr, true); 138 return 0; 139 } 140 141 #ifdef CONFIG_ACPI_CPU_FREQ_PSS 142 static int acpi_pss_perf_init(struct acpi_processor *pr, 143 struct acpi_device *device) 144 { 145 int result = 0; 146 147 acpi_processor_ppc_has_changed(pr, 0); 148 149 acpi_processor_get_throttling_info(pr); 150 151 if (pr->flags.throttling) 152 pr->flags.limit = 1; 153 154 pr->cdev = thermal_cooling_device_register("Processor", device, 155 &processor_cooling_ops); 156 if (IS_ERR(pr->cdev)) { 157 result = PTR_ERR(pr->cdev); 158 return result; 159 } 160 161 dev_dbg(&device->dev, "registered as cooling_device%d\n", 162 pr->cdev->id); 163 164 result = sysfs_create_link(&device->dev.kobj, 165 &pr->cdev->device.kobj, 166 "thermal_cooling"); 167 if (result) { 168 dev_err(&device->dev, 169 "Failed to create sysfs link 'thermal_cooling'\n"); 170 goto err_thermal_unregister; 171 } 172 173 result = sysfs_create_link(&pr->cdev->device.kobj, 174 &device->dev.kobj, 175 "device"); 176 if (result) { 177 dev_err(&pr->cdev->device, 178 "Failed to create sysfs link 'device'\n"); 179 goto err_remove_sysfs_thermal; 180 } 181 182 return 0; 183 184 err_remove_sysfs_thermal: 185 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 186 err_thermal_unregister: 187 thermal_cooling_device_unregister(pr->cdev); 188 189 return result; 190 } 191 192 static void acpi_pss_perf_exit(struct acpi_processor *pr, 193 struct acpi_device *device) 194 { 195 if (pr->cdev) { 196 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 197 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 198 thermal_cooling_device_unregister(pr->cdev); 199 pr->cdev = NULL; 200 } 201 } 202 #else 203 static inline int acpi_pss_perf_init(struct acpi_processor *pr, 204 struct acpi_device *device) 205 { 206 return 0; 207 } 208 209 static inline void acpi_pss_perf_exit(struct acpi_processor *pr, 210 struct acpi_device *device) {} 211 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */ 212 213 static int __acpi_processor_start(struct acpi_device *device) 214 { 215 struct acpi_processor *pr = acpi_driver_data(device); 216 acpi_status status; 217 int result = 0; 218 219 if (!pr) 220 return -ENODEV; 221 222 if (pr->flags.need_hotplug_init) 223 return 0; 224 225 result = acpi_cppc_processor_probe(pr); 226 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS)) 227 dev_dbg(&device->dev, "CPPC data invalid or not present\n"); 228 229 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 230 acpi_processor_power_init(pr); 231 232 result = acpi_pss_perf_init(pr, device); 233 if (result) 234 goto err_power_exit; 235 236 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 237 acpi_processor_notify, device); 238 if (ACPI_SUCCESS(status)) 239 return 0; 240 241 result = -ENODEV; 242 acpi_pss_perf_exit(pr, device); 243 244 err_power_exit: 245 acpi_processor_power_exit(pr); 246 return result; 247 } 248 249 static int acpi_processor_start(struct device *dev) 250 { 251 struct acpi_device *device = ACPI_COMPANION(dev); 252 int ret; 253 254 if (!device) 255 return -ENODEV; 256 257 /* Protect against concurrent CPU hotplug operations */ 258 cpu_hotplug_disable(); 259 ret = __acpi_processor_start(device); 260 cpu_hotplug_enable(); 261 return ret; 262 } 263 264 static int acpi_processor_stop(struct device *dev) 265 { 266 struct acpi_device *device = ACPI_COMPANION(dev); 267 struct acpi_processor *pr; 268 269 if (!device) 270 return 0; 271 272 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 273 acpi_processor_notify); 274 275 pr = acpi_driver_data(device); 276 if (!pr) 277 return 0; 278 acpi_processor_power_exit(pr); 279 280 acpi_pss_perf_exit(pr, device); 281 282 acpi_cppc_processor_exit(pr); 283 284 return 0; 285 } 286 287 bool acpi_processor_cpufreq_init; 288 289 static int acpi_processor_notifier(struct notifier_block *nb, 290 unsigned long event, void *data) 291 { 292 struct cpufreq_policy *policy = data; 293 294 if (event == CPUFREQ_CREATE_POLICY) { 295 acpi_thermal_cpufreq_init(policy); 296 acpi_processor_ppc_init(policy); 297 } else if (event == CPUFREQ_REMOVE_POLICY) { 298 acpi_processor_ppc_exit(policy); 299 acpi_thermal_cpufreq_exit(policy); 300 } 301 302 return 0; 303 } 304 305 static struct notifier_block acpi_processor_notifier_block = { 306 .notifier_call = acpi_processor_notifier, 307 }; 308 309 /* 310 * We keep the driver loaded even when ACPI is not running. 311 * This is needed for the powernow-k8 driver, that works even without 312 * ACPI, but needs symbols from this driver 313 */ 314 static enum cpuhp_state hp_online; 315 static int __init acpi_processor_driver_init(void) 316 { 317 int result = 0; 318 319 if (acpi_disabled) 320 return 0; 321 322 result = driver_register(&acpi_processor_driver); 323 if (result < 0) 324 return result; 325 326 result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, 327 "acpi/cpu-drv:online", 328 acpi_soft_cpu_online, NULL); 329 if (result < 0) 330 goto err; 331 hp_online = result; 332 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead", 333 NULL, acpi_soft_cpu_dead); 334 335 if (!cpufreq_register_notifier(&acpi_processor_notifier_block, 336 CPUFREQ_POLICY_NOTIFIER)) { 337 acpi_processor_cpufreq_init = true; 338 acpi_processor_ignore_ppc_init(); 339 } 340 341 acpi_processor_throttling_init(); 342 return 0; 343 err: 344 driver_unregister(&acpi_processor_driver); 345 return result; 346 } 347 348 static void __exit acpi_processor_driver_exit(void) 349 { 350 if (acpi_disabled) 351 return; 352 353 if (acpi_processor_cpufreq_init) { 354 cpufreq_unregister_notifier(&acpi_processor_notifier_block, 355 CPUFREQ_POLICY_NOTIFIER); 356 acpi_processor_cpufreq_init = false; 357 } 358 359 cpuhp_remove_state_nocalls(hp_online); 360 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD); 361 driver_unregister(&acpi_processor_driver); 362 } 363 364 module_init(acpi_processor_driver_init); 365 module_exit(acpi_processor_driver_exit); 366 367 MODULE_ALIAS("processor"); 368