1 /* 2 * processor_driver.c - ACPI Processor Driver 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de> 7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 8 * - Added processor hotplug support 9 * Copyright (C) 2013, Intel Corporation 10 * Rafael J. Wysocki <rafael.j.wysocki@intel.com> 11 * 12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License as published by 16 * the Free Software Foundation; either version 2 of the License, or (at 17 * your option) any later version. 18 * 19 * This program is distributed in the hope that it will be useful, but 20 * WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 * General Public License for more details. 23 * 24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 25 */ 26 27 #include <linux/kernel.h> 28 #include <linux/module.h> 29 #include <linux/init.h> 30 #include <linux/cpufreq.h> 31 #include <linux/cpu.h> 32 #include <linux/cpuidle.h> 33 #include <linux/slab.h> 34 #include <linux/acpi.h> 35 36 #include <acpi/processor.h> 37 38 #include "internal.h" 39 40 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80 41 #define ACPI_PROCESSOR_NOTIFY_POWER 0x81 42 #define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82 43 44 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 45 ACPI_MODULE_NAME("processor_driver"); 46 47 MODULE_AUTHOR("Paul Diefenbaugh"); 48 MODULE_DESCRIPTION("ACPI Processor Driver"); 49 MODULE_LICENSE("GPL"); 50 51 static int acpi_processor_start(struct device *dev); 52 static int acpi_processor_stop(struct device *dev); 53 54 static const struct acpi_device_id processor_device_ids[] = { 55 {ACPI_PROCESSOR_OBJECT_HID, 0}, 56 {ACPI_PROCESSOR_DEVICE_HID, 0}, 57 {"", 0}, 58 }; 59 MODULE_DEVICE_TABLE(acpi, processor_device_ids); 60 61 static struct device_driver acpi_processor_driver = { 62 .name = "processor", 63 .bus = &cpu_subsys, 64 .acpi_match_table = processor_device_ids, 65 .probe = acpi_processor_start, 66 .remove = acpi_processor_stop, 67 }; 68 69 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data) 70 { 71 struct acpi_device *device = data; 72 struct acpi_processor *pr; 73 int saved; 74 75 if (device->handle != handle) 76 return; 77 78 pr = acpi_driver_data(device); 79 if (!pr) 80 return; 81 82 switch (event) { 83 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE: 84 saved = pr->performance_platform_limit; 85 acpi_processor_ppc_has_changed(pr, 1); 86 if (saved == pr->performance_platform_limit) 87 break; 88 acpi_bus_generate_netlink_event(device->pnp.device_class, 89 dev_name(&device->dev), event, 90 pr->performance_platform_limit); 91 break; 92 case ACPI_PROCESSOR_NOTIFY_POWER: 93 acpi_processor_cst_has_changed(pr); 94 acpi_bus_generate_netlink_event(device->pnp.device_class, 95 dev_name(&device->dev), event, 0); 96 break; 97 case ACPI_PROCESSOR_NOTIFY_THROTTLING: 98 acpi_processor_tstate_has_changed(pr); 99 acpi_bus_generate_netlink_event(device->pnp.device_class, 100 dev_name(&device->dev), event, 0); 101 break; 102 default: 103 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 104 "Unsupported event [0x%x]\n", event)); 105 break; 106 } 107 108 return; 109 } 110 111 static int __acpi_processor_start(struct acpi_device *device); 112 113 static int acpi_cpu_soft_notify(struct notifier_block *nfb, 114 unsigned long action, void *hcpu) 115 { 116 unsigned int cpu = (unsigned long)hcpu; 117 struct acpi_processor *pr = per_cpu(processors, cpu); 118 struct acpi_device *device; 119 action &= ~CPU_TASKS_FROZEN; 120 121 /* 122 * CPU_STARTING and CPU_DYING must not sleep. Return here since 123 * acpi_bus_get_device() may sleep. 124 */ 125 if (action == CPU_STARTING || action == CPU_DYING) 126 return NOTIFY_DONE; 127 128 if (!pr || acpi_bus_get_device(pr->handle, &device)) 129 return NOTIFY_DONE; 130 131 if (action == CPU_ONLINE) { 132 /* 133 * CPU got physically hotplugged and onlined for the first time: 134 * Initialize missing things. 135 */ 136 if (pr->flags.need_hotplug_init) { 137 int ret; 138 139 pr_info("Will online and init hotplugged CPU: %d\n", 140 pr->id); 141 pr->flags.need_hotplug_init = 0; 142 ret = __acpi_processor_start(device); 143 WARN(ret, "Failed to start CPU: %d\n", pr->id); 144 } else { 145 /* Normal CPU soft online event. */ 146 acpi_processor_ppc_has_changed(pr, 0); 147 acpi_processor_hotplug(pr); 148 acpi_processor_reevaluate_tstate(pr, action); 149 acpi_processor_tstate_has_changed(pr); 150 } 151 } else if (action == CPU_DEAD) { 152 /* Invalidate flag.throttling after the CPU is offline. */ 153 acpi_processor_reevaluate_tstate(pr, action); 154 } 155 return NOTIFY_OK; 156 } 157 158 static struct notifier_block acpi_cpu_notifier = { 159 .notifier_call = acpi_cpu_soft_notify, 160 }; 161 162 #ifdef CONFIG_ACPI_CPU_FREQ_PSS 163 static int acpi_pss_perf_init(struct acpi_processor *pr, 164 struct acpi_device *device) 165 { 166 int result = 0; 167 168 acpi_processor_ppc_has_changed(pr, 0); 169 170 acpi_processor_get_throttling_info(pr); 171 172 if (pr->flags.throttling) 173 pr->flags.limit = 1; 174 175 pr->cdev = thermal_cooling_device_register("Processor", device, 176 &processor_cooling_ops); 177 if (IS_ERR(pr->cdev)) { 178 result = PTR_ERR(pr->cdev); 179 return result; 180 } 181 182 dev_dbg(&device->dev, "registered as cooling_device%d\n", 183 pr->cdev->id); 184 185 result = sysfs_create_link(&device->dev.kobj, 186 &pr->cdev->device.kobj, 187 "thermal_cooling"); 188 if (result) { 189 dev_err(&device->dev, 190 "Failed to create sysfs link 'thermal_cooling'\n"); 191 goto err_thermal_unregister; 192 } 193 194 result = sysfs_create_link(&pr->cdev->device.kobj, 195 &device->dev.kobj, 196 "device"); 197 if (result) { 198 dev_err(&pr->cdev->device, 199 "Failed to create sysfs link 'device'\n"); 200 goto err_remove_sysfs_thermal; 201 } 202 203 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 204 err_remove_sysfs_thermal: 205 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 206 err_thermal_unregister: 207 thermal_cooling_device_unregister(pr->cdev); 208 209 return result; 210 } 211 212 static void acpi_pss_perf_exit(struct acpi_processor *pr, 213 struct acpi_device *device) 214 { 215 if (pr->cdev) { 216 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 217 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 218 thermal_cooling_device_unregister(pr->cdev); 219 pr->cdev = NULL; 220 } 221 } 222 #else 223 static inline int acpi_pss_perf_init(struct acpi_processor *pr, 224 struct acpi_device *device) 225 { 226 return 0; 227 } 228 229 static inline void acpi_pss_perf_exit(struct acpi_processor *pr, 230 struct acpi_device *device) {} 231 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */ 232 233 static int __acpi_processor_start(struct acpi_device *device) 234 { 235 struct acpi_processor *pr = acpi_driver_data(device); 236 acpi_status status; 237 int result = 0; 238 239 if (!pr) 240 return -ENODEV; 241 242 if (pr->flags.need_hotplug_init) 243 return 0; 244 245 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 246 acpi_processor_power_init(pr); 247 248 result = acpi_pss_perf_init(pr, device); 249 if (result) 250 goto err_power_exit; 251 252 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 253 acpi_processor_notify, device); 254 if (ACPI_SUCCESS(status)) 255 return 0; 256 257 err_power_exit: 258 acpi_processor_power_exit(pr); 259 return result; 260 } 261 262 static int acpi_processor_start(struct device *dev) 263 { 264 struct acpi_device *device = ACPI_COMPANION(dev); 265 266 if (!device) 267 return -ENODEV; 268 269 return __acpi_processor_start(device); 270 } 271 272 static int acpi_processor_stop(struct device *dev) 273 { 274 struct acpi_device *device = ACPI_COMPANION(dev); 275 struct acpi_processor *pr; 276 277 if (!device) 278 return 0; 279 280 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 281 acpi_processor_notify); 282 283 pr = acpi_driver_data(device); 284 if (!pr) 285 return 0; 286 acpi_processor_power_exit(pr); 287 288 acpi_pss_perf_exit(pr, device); 289 290 return 0; 291 } 292 293 /* 294 * We keep the driver loaded even when ACPI is not running. 295 * This is needed for the powernow-k8 driver, that works even without 296 * ACPI, but needs symbols from this driver 297 */ 298 299 static int __init acpi_processor_driver_init(void) 300 { 301 int result = 0; 302 303 if (acpi_disabled) 304 return 0; 305 306 result = driver_register(&acpi_processor_driver); 307 if (result < 0) 308 return result; 309 310 acpi_processor_syscore_init(); 311 register_hotcpu_notifier(&acpi_cpu_notifier); 312 acpi_thermal_cpufreq_init(); 313 acpi_processor_ppc_init(); 314 acpi_processor_throttling_init(); 315 return 0; 316 } 317 318 static void __exit acpi_processor_driver_exit(void) 319 { 320 if (acpi_disabled) 321 return; 322 323 acpi_processor_ppc_exit(); 324 acpi_thermal_cpufreq_exit(); 325 unregister_hotcpu_notifier(&acpi_cpu_notifier); 326 acpi_processor_syscore_exit(); 327 driver_unregister(&acpi_processor_driver); 328 } 329 330 module_init(acpi_processor_driver_init); 331 module_exit(acpi_processor_driver_exit); 332 333 MODULE_ALIAS("processor"); 334