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