1 /* 2 * processor_driver.c - ACPI Processor Driver 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <[email protected]> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]> 6 * Copyright (C) 2004 Dominik Brodowski <[email protected]> 7 * Copyright (C) 2004 Anil S Keshavamurthy <[email protected]> 8 * - Added processor hotplug support 9 * Copyright (C) 2013, Intel Corporation 10 * Rafael J. Wysocki <[email protected]> 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 __refdata acpi_cpu_notifier = { 159 .notifier_call = acpi_cpu_soft_notify, 160 }; 161 162 static int __acpi_processor_start(struct acpi_device *device) 163 { 164 struct acpi_processor *pr = acpi_driver_data(device); 165 acpi_status status; 166 int result = 0; 167 168 if (!pr) 169 return -ENODEV; 170 171 if (pr->flags.need_hotplug_init) 172 return 0; 173 174 #ifdef CONFIG_CPU_FREQ 175 acpi_processor_ppc_has_changed(pr, 0); 176 #endif 177 acpi_processor_get_throttling_info(pr); 178 179 if (pr->flags.throttling) 180 pr->flags.limit = 1; 181 182 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 183 acpi_processor_power_init(pr); 184 185 pr->cdev = thermal_cooling_device_register("Processor", device, 186 &processor_cooling_ops); 187 if (IS_ERR(pr->cdev)) { 188 result = PTR_ERR(pr->cdev); 189 goto err_power_exit; 190 } 191 192 dev_dbg(&device->dev, "registered as cooling_device%d\n", 193 pr->cdev->id); 194 195 result = sysfs_create_link(&device->dev.kobj, 196 &pr->cdev->device.kobj, 197 "thermal_cooling"); 198 if (result) { 199 dev_err(&device->dev, 200 "Failed to create sysfs link 'thermal_cooling'\n"); 201 goto err_thermal_unregister; 202 } 203 result = sysfs_create_link(&pr->cdev->device.kobj, 204 &device->dev.kobj, 205 "device"); 206 if (result) { 207 dev_err(&pr->cdev->device, 208 "Failed to create sysfs link 'device'\n"); 209 goto err_remove_sysfs_thermal; 210 } 211 212 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 213 acpi_processor_notify, device); 214 if (ACPI_SUCCESS(status)) 215 return 0; 216 217 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 218 err_remove_sysfs_thermal: 219 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 220 err_thermal_unregister: 221 thermal_cooling_device_unregister(pr->cdev); 222 err_power_exit: 223 acpi_processor_power_exit(pr); 224 return result; 225 } 226 227 static int acpi_processor_start(struct device *dev) 228 { 229 struct acpi_device *device = ACPI_COMPANION(dev); 230 231 if (!device) 232 return -ENODEV; 233 234 return __acpi_processor_start(device); 235 } 236 237 static int acpi_processor_stop(struct device *dev) 238 { 239 struct acpi_device *device = ACPI_COMPANION(dev); 240 struct acpi_processor *pr; 241 242 if (!device) 243 return 0; 244 245 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 246 acpi_processor_notify); 247 248 pr = acpi_driver_data(device); 249 if (!pr) 250 return 0; 251 252 acpi_processor_power_exit(pr); 253 254 if (pr->cdev) { 255 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 256 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 257 thermal_cooling_device_unregister(pr->cdev); 258 pr->cdev = NULL; 259 } 260 return 0; 261 } 262 263 /* 264 * We keep the driver loaded even when ACPI is not running. 265 * This is needed for the powernow-k8 driver, that works even without 266 * ACPI, but needs symbols from this driver 267 */ 268 269 static int __init acpi_processor_driver_init(void) 270 { 271 int result = 0; 272 273 if (acpi_disabled) 274 return 0; 275 276 result = driver_register(&acpi_processor_driver); 277 if (result < 0) 278 return result; 279 280 acpi_processor_syscore_init(); 281 register_hotcpu_notifier(&acpi_cpu_notifier); 282 acpi_thermal_cpufreq_init(); 283 acpi_processor_ppc_init(); 284 acpi_processor_throttling_init(); 285 return 0; 286 } 287 288 static void __exit acpi_processor_driver_exit(void) 289 { 290 if (acpi_disabled) 291 return; 292 293 acpi_processor_ppc_exit(); 294 acpi_thermal_cpufreq_exit(); 295 unregister_hotcpu_notifier(&acpi_cpu_notifier); 296 acpi_processor_syscore_exit(); 297 driver_unregister(&acpi_processor_driver); 298 } 299 300 module_init(acpi_processor_driver_init); 301 module_exit(acpi_processor_driver_exit); 302 303 MODULE_ALIAS("processor"); 304