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 PREFIX "ACPI: " 45 46 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80 47 #define ACPI_PROCESSOR_NOTIFY_POWER 0x81 48 #define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82 49 50 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 51 ACPI_MODULE_NAME("processor_driver"); 52 53 MODULE_AUTHOR("Paul Diefenbaugh"); 54 MODULE_DESCRIPTION("ACPI Processor Driver"); 55 MODULE_LICENSE("GPL"); 56 57 static int acpi_processor_start(struct device *dev); 58 static int acpi_processor_stop(struct device *dev); 59 60 static const struct acpi_device_id processor_device_ids[] = { 61 {ACPI_PROCESSOR_OBJECT_HID, 0}, 62 {ACPI_PROCESSOR_DEVICE_HID, 0}, 63 {"", 0}, 64 }; 65 MODULE_DEVICE_TABLE(acpi, processor_device_ids); 66 67 static struct device_driver acpi_processor_driver = { 68 .name = "processor", 69 .bus = &cpu_subsys, 70 .acpi_match_table = processor_device_ids, 71 .probe = acpi_processor_start, 72 .remove = acpi_processor_stop, 73 }; 74 75 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data) 76 { 77 struct acpi_device *device = data; 78 struct acpi_processor *pr; 79 int saved; 80 81 if (device->handle != handle) 82 return; 83 84 pr = acpi_driver_data(device); 85 if (!pr) 86 return; 87 88 switch (event) { 89 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE: 90 saved = pr->performance_platform_limit; 91 acpi_processor_ppc_has_changed(pr, 1); 92 if (saved == pr->performance_platform_limit) 93 break; 94 acpi_bus_generate_proc_event(device, event, 95 pr->performance_platform_limit); 96 acpi_bus_generate_netlink_event(device->pnp.device_class, 97 dev_name(&device->dev), event, 98 pr->performance_platform_limit); 99 break; 100 case ACPI_PROCESSOR_NOTIFY_POWER: 101 acpi_processor_cst_has_changed(pr); 102 acpi_bus_generate_proc_event(device, event, 0); 103 acpi_bus_generate_netlink_event(device->pnp.device_class, 104 dev_name(&device->dev), event, 0); 105 break; 106 case ACPI_PROCESSOR_NOTIFY_THROTTLING: 107 acpi_processor_tstate_has_changed(pr); 108 acpi_bus_generate_proc_event(device, event, 0); 109 acpi_bus_generate_netlink_event(device->pnp.device_class, 110 dev_name(&device->dev), event, 0); 111 break; 112 default: 113 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 114 "Unsupported event [0x%x]\n", event)); 115 break; 116 } 117 118 return; 119 } 120 121 static int __acpi_processor_start(struct acpi_device *device); 122 123 static int acpi_cpu_soft_notify(struct notifier_block *nfb, 124 unsigned long action, void *hcpu) 125 { 126 unsigned int cpu = (unsigned long)hcpu; 127 struct acpi_processor *pr = per_cpu(processors, cpu); 128 struct acpi_device *device; 129 130 if (!pr || acpi_bus_get_device(pr->handle, &device)) 131 return NOTIFY_DONE; 132 133 if (action == CPU_ONLINE) { 134 /* 135 * CPU got physically hotplugged and onlined for the first time: 136 * Initialize missing things. 137 */ 138 if (pr->flags.need_hotplug_init) { 139 int ret; 140 141 pr_info("Will online and init hotplugged CPU: %d\n", 142 pr->id); 143 pr->flags.need_hotplug_init = 0; 144 ret = __acpi_processor_start(device); 145 WARN(ret, "Failed to start CPU: %d\n", pr->id); 146 } else { 147 /* Normal CPU soft online event. */ 148 acpi_processor_ppc_has_changed(pr, 0); 149 acpi_processor_hotplug(pr); 150 acpi_processor_reevaluate_tstate(pr, action); 151 acpi_processor_tstate_has_changed(pr); 152 } 153 } else if (action == CPU_DEAD) { 154 /* Invalidate flag.throttling after the CPU is offline. */ 155 acpi_processor_reevaluate_tstate(pr, action); 156 } 157 return NOTIFY_OK; 158 } 159 160 static struct notifier_block __refdata acpi_cpu_notifier = 161 { 162 .notifier_call = acpi_cpu_soft_notify, 163 }; 164 165 static int __acpi_processor_start(struct acpi_device *device) 166 { 167 struct acpi_processor *pr = acpi_driver_data(device); 168 acpi_status status; 169 int result = 0; 170 171 if (!pr) 172 return -ENODEV; 173 174 if (pr->flags.need_hotplug_init) 175 return 0; 176 177 #ifdef CONFIG_CPU_FREQ 178 acpi_processor_ppc_has_changed(pr, 0); 179 acpi_processor_load_module(pr); 180 #endif 181 acpi_processor_get_throttling_info(pr); 182 acpi_processor_get_limit_info(pr); 183 184 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 185 acpi_processor_power_init(pr); 186 187 pr->cdev = thermal_cooling_device_register("Processor", device, 188 &processor_cooling_ops); 189 if (IS_ERR(pr->cdev)) { 190 result = PTR_ERR(pr->cdev); 191 goto err_power_exit; 192 } 193 194 dev_dbg(&device->dev, "registered as cooling_device%d\n", 195 pr->cdev->id); 196 197 result = sysfs_create_link(&device->dev.kobj, 198 &pr->cdev->device.kobj, 199 "thermal_cooling"); 200 if (result) { 201 dev_err(&device->dev, 202 "Failed to create sysfs link 'thermal_cooling'\n"); 203 goto err_thermal_unregister; 204 } 205 result = sysfs_create_link(&pr->cdev->device.kobj, 206 &device->dev.kobj, 207 "device"); 208 if (result) { 209 dev_err(&pr->cdev->device, 210 "Failed to create sysfs link 'device'\n"); 211 goto err_remove_sysfs_thermal; 212 } 213 214 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 215 acpi_processor_notify, device); 216 if (ACPI_SUCCESS(status)) 217 return 0; 218 219 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 220 err_remove_sysfs_thermal: 221 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 222 err_thermal_unregister: 223 thermal_cooling_device_unregister(pr->cdev); 224 err_power_exit: 225 acpi_processor_power_exit(pr); 226 return result; 227 } 228 229 static int acpi_processor_start(struct device *dev) 230 { 231 struct acpi_device *device; 232 233 if (acpi_bus_get_device(ACPI_HANDLE(dev), &device)) 234 return -ENODEV; 235 236 return __acpi_processor_start(device); 237 } 238 239 static int acpi_processor_stop(struct device *dev) 240 { 241 struct acpi_device *device; 242 struct acpi_processor *pr; 243 244 if (acpi_bus_get_device(ACPI_HANDLE(dev), &device)) 245 return 0; 246 247 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 248 acpi_processor_notify); 249 250 pr = acpi_driver_data(device); 251 if (!pr) 252 return 0; 253 254 acpi_processor_power_exit(pr); 255 256 if (pr->cdev) { 257 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 258 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 259 thermal_cooling_device_unregister(pr->cdev); 260 pr->cdev = NULL; 261 } 262 return 0; 263 } 264 265 /* 266 * We keep the driver loaded even when ACPI is not running. 267 * This is needed for the powernow-k8 driver, that works even without 268 * ACPI, but needs symbols from this driver 269 */ 270 271 static int __init acpi_processor_driver_init(void) 272 { 273 int result = 0; 274 275 if (acpi_disabled) 276 return 0; 277 278 result = driver_register(&acpi_processor_driver); 279 if (result < 0) 280 return result; 281 282 acpi_processor_syscore_init(); 283 register_hotcpu_notifier(&acpi_cpu_notifier); 284 acpi_thermal_cpufreq_init(); 285 acpi_processor_ppc_init(); 286 acpi_processor_throttling_init(); 287 return 0; 288 } 289 290 static void __exit acpi_processor_driver_exit(void) 291 { 292 if (acpi_disabled) 293 return; 294 295 acpi_processor_ppc_exit(); 296 acpi_thermal_cpufreq_exit(); 297 unregister_hotcpu_notifier(&acpi_cpu_notifier); 298 acpi_processor_syscore_exit(); 299 driver_unregister(&acpi_processor_driver); 300 } 301 302 module_init(acpi_processor_driver_init); 303 module_exit(acpi_processor_driver_exit); 304 305 MODULE_ALIAS("processor"); 306