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 * You should have received a copy of the GNU General Public License along 25 * with this program; if not, write to the Free Software Foundation, Inc., 26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 27 * 28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 29 */ 30 31 #include <linux/kernel.h> 32 #include <linux/module.h> 33 #include <linux/init.h> 34 #include <linux/cpufreq.h> 35 #include <linux/cpu.h> 36 #include <linux/cpuidle.h> 37 #include <linux/slab.h> 38 #include <linux/acpi.h> 39 40 #include <acpi/processor.h> 41 42 #include "internal.h" 43 44 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80 45 #define ACPI_PROCESSOR_NOTIFY_POWER 0x81 46 #define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82 47 48 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 49 ACPI_MODULE_NAME("processor_driver"); 50 51 MODULE_AUTHOR("Paul Diefenbaugh"); 52 MODULE_DESCRIPTION("ACPI Processor Driver"); 53 MODULE_LICENSE("GPL"); 54 55 static int acpi_processor_start(struct device *dev); 56 static int acpi_processor_stop(struct device *dev); 57 58 static const struct acpi_device_id processor_device_ids[] = { 59 {ACPI_PROCESSOR_OBJECT_HID, 0}, 60 {ACPI_PROCESSOR_DEVICE_HID, 0}, 61 {"", 0}, 62 }; 63 MODULE_DEVICE_TABLE(acpi, processor_device_ids); 64 65 static struct device_driver acpi_processor_driver = { 66 .name = "processor", 67 .bus = &cpu_subsys, 68 .acpi_match_table = processor_device_ids, 69 .probe = acpi_processor_start, 70 .remove = acpi_processor_stop, 71 }; 72 73 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data) 74 { 75 struct acpi_device *device = data; 76 struct acpi_processor *pr; 77 int saved; 78 79 if (device->handle != handle) 80 return; 81 82 pr = acpi_driver_data(device); 83 if (!pr) 84 return; 85 86 switch (event) { 87 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE: 88 saved = pr->performance_platform_limit; 89 acpi_processor_ppc_has_changed(pr, 1); 90 if (saved == pr->performance_platform_limit) 91 break; 92 acpi_bus_generate_netlink_event(device->pnp.device_class, 93 dev_name(&device->dev), event, 94 pr->performance_platform_limit); 95 break; 96 case ACPI_PROCESSOR_NOTIFY_POWER: 97 acpi_processor_cst_has_changed(pr); 98 acpi_bus_generate_netlink_event(device->pnp.device_class, 99 dev_name(&device->dev), event, 0); 100 break; 101 case ACPI_PROCESSOR_NOTIFY_THROTTLING: 102 acpi_processor_tstate_has_changed(pr); 103 acpi_bus_generate_netlink_event(device->pnp.device_class, 104 dev_name(&device->dev), event, 0); 105 break; 106 default: 107 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 108 "Unsupported event [0x%x]\n", event)); 109 break; 110 } 111 112 return; 113 } 114 115 static int __acpi_processor_start(struct acpi_device *device); 116 117 static int acpi_cpu_soft_notify(struct notifier_block *nfb, 118 unsigned long action, void *hcpu) 119 { 120 unsigned int cpu = (unsigned long)hcpu; 121 struct acpi_processor *pr = per_cpu(processors, cpu); 122 struct acpi_device *device; 123 124 if (!pr || acpi_bus_get_device(pr->handle, &device)) 125 return NOTIFY_DONE; 126 127 if (action == CPU_ONLINE) { 128 /* 129 * CPU got physically hotplugged and onlined for the first time: 130 * Initialize missing things. 131 */ 132 if (pr->flags.need_hotplug_init) { 133 int ret; 134 135 pr_info("Will online and init hotplugged CPU: %d\n", 136 pr->id); 137 pr->flags.need_hotplug_init = 0; 138 ret = __acpi_processor_start(device); 139 WARN(ret, "Failed to start CPU: %d\n", pr->id); 140 } else { 141 /* Normal CPU soft online event. */ 142 acpi_processor_ppc_has_changed(pr, 0); 143 acpi_processor_hotplug(pr); 144 acpi_processor_reevaluate_tstate(pr, action); 145 acpi_processor_tstate_has_changed(pr); 146 } 147 } else if (action == CPU_DEAD) { 148 /* Invalidate flag.throttling after the CPU is offline. */ 149 acpi_processor_reevaluate_tstate(pr, action); 150 } 151 return NOTIFY_OK; 152 } 153 154 static struct notifier_block __refdata acpi_cpu_notifier = { 155 .notifier_call = acpi_cpu_soft_notify, 156 }; 157 158 static int __acpi_processor_start(struct acpi_device *device) 159 { 160 struct acpi_processor *pr = acpi_driver_data(device); 161 acpi_status status; 162 int result = 0; 163 164 if (!pr) 165 return -ENODEV; 166 167 if (pr->flags.need_hotplug_init) 168 return 0; 169 170 #ifdef CONFIG_CPU_FREQ 171 acpi_processor_ppc_has_changed(pr, 0); 172 #endif 173 acpi_processor_get_throttling_info(pr); 174 175 if (pr->flags.throttling) 176 pr->flags.limit = 1; 177 178 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 179 acpi_processor_power_init(pr); 180 181 pr->cdev = thermal_cooling_device_register("Processor", device, 182 &processor_cooling_ops); 183 if (IS_ERR(pr->cdev)) { 184 result = PTR_ERR(pr->cdev); 185 goto err_power_exit; 186 } 187 188 dev_dbg(&device->dev, "registered as cooling_device%d\n", 189 pr->cdev->id); 190 191 result = sysfs_create_link(&device->dev.kobj, 192 &pr->cdev->device.kobj, 193 "thermal_cooling"); 194 if (result) { 195 dev_err(&device->dev, 196 "Failed to create sysfs link 'thermal_cooling'\n"); 197 goto err_thermal_unregister; 198 } 199 result = sysfs_create_link(&pr->cdev->device.kobj, 200 &device->dev.kobj, 201 "device"); 202 if (result) { 203 dev_err(&pr->cdev->device, 204 "Failed to create sysfs link 'device'\n"); 205 goto err_remove_sysfs_thermal; 206 } 207 208 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 209 acpi_processor_notify, device); 210 if (ACPI_SUCCESS(status)) 211 return 0; 212 213 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 214 err_remove_sysfs_thermal: 215 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 216 err_thermal_unregister: 217 thermal_cooling_device_unregister(pr->cdev); 218 err_power_exit: 219 acpi_processor_power_exit(pr); 220 return result; 221 } 222 223 static int acpi_processor_start(struct device *dev) 224 { 225 struct acpi_device *device = ACPI_COMPANION(dev); 226 227 if (!device) 228 return -ENODEV; 229 230 return __acpi_processor_start(device); 231 } 232 233 static int acpi_processor_stop(struct device *dev) 234 { 235 struct acpi_device *device = ACPI_COMPANION(dev); 236 struct acpi_processor *pr; 237 238 if (!device) 239 return 0; 240 241 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 242 acpi_processor_notify); 243 244 pr = acpi_driver_data(device); 245 if (!pr) 246 return 0; 247 248 acpi_processor_power_exit(pr); 249 250 if (pr->cdev) { 251 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 252 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 253 thermal_cooling_device_unregister(pr->cdev); 254 pr->cdev = NULL; 255 } 256 return 0; 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 */ 264 265 static int __init acpi_processor_driver_init(void) 266 { 267 int result = 0; 268 269 if (acpi_disabled) 270 return 0; 271 272 result = driver_register(&acpi_processor_driver); 273 if (result < 0) 274 return result; 275 276 acpi_processor_syscore_init(); 277 register_hotcpu_notifier(&acpi_cpu_notifier); 278 acpi_thermal_cpufreq_init(); 279 acpi_processor_ppc_init(); 280 acpi_processor_throttling_init(); 281 return 0; 282 } 283 284 static void __exit acpi_processor_driver_exit(void) 285 { 286 if (acpi_disabled) 287 return; 288 289 acpi_processor_ppc_exit(); 290 acpi_thermal_cpufreq_exit(); 291 unregister_hotcpu_notifier(&acpi_cpu_notifier); 292 acpi_processor_syscore_exit(); 293 driver_unregister(&acpi_processor_driver); 294 } 295 296 module_init(acpi_processor_driver_init); 297 module_exit(acpi_processor_driver_exit); 298 299 MODULE_ALIAS("processor"); 300