drivers/acpi/processor_driver.c

   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_FILE_INFO        "info"
  47 #define ACPI_PROCESSOR_FILE_THROTTLING  "throttling"
  48 #define ACPI_PROCESSOR_FILE_LIMIT       "limit"
  49 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
  50 #define ACPI_PROCESSOR_NOTIFY_POWER     0x81
  51 #define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
  52
  53 #define ACPI_PROCESSOR_LIMIT_USER       0
  54 #define ACPI_PROCESSOR_LIMIT_THERMAL    1
  55
  56 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  57 ACPI_MODULE_NAME("processor_driver");
  58
  59 MODULE_AUTHOR("Paul Diefenbaugh");
  60 MODULE_DESCRIPTION("ACPI Processor Driver");
  61 MODULE_LICENSE("GPL");
  62
  63 static int acpi_processor_start(struct device *dev);
  64 static int acpi_processor_stop(struct device *dev);
  65
  66 static const struct acpi_device_id processor_device_ids[] = {
  67         {ACPI_PROCESSOR_OBJECT_HID, 0},
  68         {ACPI_PROCESSOR_DEVICE_HID, 0},
  69         {"", 0},
  70 };
  71 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  72
  73 static struct device_driver acpi_processor_driver = {
  74         .name = "processor",
  75         .bus = &cpu_subsys,
  76         .acpi_match_table = processor_device_ids,
  77         .probe = acpi_processor_start,
  78         .remove = acpi_processor_stop,
  79 };
  80
  81 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
  82 {
  83         struct acpi_device *device = data;
  84         struct acpi_processor *pr;
  85         int saved;
  86
  87         if (device->handle != handle)
  88                 return;
  89
  90         pr = acpi_driver_data(device);
  91         if (!pr)
  92                 return;
  93
  94         switch (event) {
  95         case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
  96                 saved = pr->performance_platform_limit;
  97                 acpi_processor_ppc_has_changed(pr, 1);
  98                 if (saved == pr->performance_platform_limit)
  99                         break;
 100                 acpi_bus_generate_proc_event(device, event,
 101                                         pr->performance_platform_limit);
 102                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 103                                                   dev_name(&device->dev), event,
 104                                                   pr->performance_platform_limit);
 105                 break;
 106         case ACPI_PROCESSOR_NOTIFY_POWER:
 107                 acpi_processor_cst_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         case ACPI_PROCESSOR_NOTIFY_THROTTLING:
 113                 acpi_processor_tstate_has_changed(pr);
 114                 acpi_bus_generate_proc_event(device, event, 0);
 115                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 116                                                   dev_name(&device->dev), event, 0);
 117                 break;
 118         default:
 119                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 120                                   "Unsupported event [0x%x]\n", event));
 121                 break;
 122         }
 123
 124         return;
 125 }
 126
 127 static __cpuinit int __acpi_processor_start(struct acpi_device *device);
 128
 129 static int __cpuinit acpi_cpu_soft_notify(struct notifier_block *nfb,
 130                                           unsigned long action, void *hcpu)
 131 {
 132         unsigned int cpu = (unsigned long)hcpu;
 133         struct acpi_processor *pr = per_cpu(processors, cpu);
 134         struct acpi_device *device;
 135
 136         if (!pr || acpi_bus_get_device(pr->handle, &device))
 137                 return NOTIFY_DONE;
 138
 139         if (action == CPU_ONLINE) {
 140                 /*
 141                  * CPU got physically hotplugged and onlined for the first time:
 142                  * Initialize missing things.
 143                  */
 144                 if (pr->flags.need_hotplug_init) {
 145                         int ret;
 146
 147                         pr_info("Will online and init hotplugged CPU: %d\n",
 148                                 pr->id);
 149                         pr->flags.need_hotplug_init = 0;
 150                         ret = __acpi_processor_start(device);
 151                         WARN(ret, "Failed to start CPU: %d\n", pr->id);
 152                 } else {
 153                         /* Normal CPU soft online event. */
 154                         acpi_processor_ppc_has_changed(pr, 0);
 155                         acpi_processor_hotplug(pr);
 156                         acpi_processor_reevaluate_tstate(pr, action);
 157                         acpi_processor_tstate_has_changed(pr);
 158                 }
 159         } else if (action == CPU_DEAD) {
 160                 /* Invalidate flag.throttling after the CPU is offline. */
 161                 acpi_processor_reevaluate_tstate(pr, action);
 162         }
 163         return NOTIFY_OK;
 164 }
 165
 166 static struct notifier_block __refdata acpi_cpu_notifier =
 167 {
 168             .notifier_call = acpi_cpu_soft_notify,
 169 };
 170
 171 static __cpuinit int __acpi_processor_start(struct acpi_device *device)
 172 {
 173         struct acpi_processor *pr = acpi_driver_data(device);
 174         acpi_status status;
 175         int result = 0;
 176
 177         if (!pr)
 178                 return -ENODEV;
 179
 180         if (pr->flags.need_hotplug_init)
 181                 return 0;
 182
 183 #ifdef CONFIG_CPU_FREQ
 184         acpi_processor_ppc_has_changed(pr, 0);
 185         acpi_processor_load_module(pr);
 186 #endif
 187         acpi_processor_get_throttling_info(pr);
 188         acpi_processor_get_limit_info(pr);
 189
 190         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 191                 acpi_processor_power_init(pr);
 192
 193         pr->cdev = thermal_cooling_device_register("Processor", device,
 194                                                    &processor_cooling_ops);
 195         if (IS_ERR(pr->cdev)) {
 196                 result = PTR_ERR(pr->cdev);
 197                 goto err_power_exit;
 198         }
 199
 200         dev_dbg(&device->dev, "registered as cooling_device%d\n",
 201                 pr->cdev->id);
 202
 203         result = sysfs_create_link(&device->dev.kobj,
 204                                    &pr->cdev->device.kobj,
 205                                    "thermal_cooling");
 206         if (result) {
 207                 dev_err(&device->dev,
 208                         "Failed to create sysfs link 'thermal_cooling'\n");
 209                 goto err_thermal_unregister;
 210         }
 211         result = sysfs_create_link(&pr->cdev->device.kobj,
 212                                    &device->dev.kobj,
 213                                    "device");
 214         if (result) {
 215                 dev_err(&pr->cdev->device,
 216                         "Failed to create sysfs link 'device'\n");
 217                 goto err_remove_sysfs_thermal;
 218         }
 219
 220         status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 221                                              acpi_processor_notify, device);
 222         if (ACPI_SUCCESS(status))
 223                 return 0;
 224
 225         sysfs_remove_link(&pr->cdev->device.kobj, "device");
 226  err_remove_sysfs_thermal:
 227         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 228  err_thermal_unregister:
 229         thermal_cooling_device_unregister(pr->cdev);
 230  err_power_exit:
 231         acpi_processor_power_exit(pr);
 232         return result;
 233 }
 234
 235 static int __cpuinit acpi_processor_start(struct device *dev)
 236 {
 237         struct acpi_device *device;
 238
 239         if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
 240                 return -ENODEV;
 241
 242         return __acpi_processor_start(device);
 243 }
 244
 245 static int acpi_processor_stop(struct device *dev)
 246 {
 247         struct acpi_device *device;
 248         struct acpi_processor *pr;
 249
 250         if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
 251                 return 0;
 252
 253         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 254                                    acpi_processor_notify);
 255
 256         pr = acpi_driver_data(device);
 257         if (!pr)
 258                 return 0;
 259
 260         acpi_processor_power_exit(pr);
 261
 262         if (pr->cdev) {
 263                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 264                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
 265                 thermal_cooling_device_unregister(pr->cdev);
 266                 pr->cdev = NULL;
 267         }
 268         return 0;
 269 }
 270
 271 /*
 272  * We keep the driver loaded even when ACPI is not running.
 273  * This is needed for the powernow-k8 driver, that works even without
 274  * ACPI, but needs symbols from this driver
 275  */
 276
 277 static int __init acpi_processor_driver_init(void)
 278 {
 279         int result = 0;
 280
 281         if (acpi_disabled)
 282                 return 0;
 283
 284         result = driver_register(&acpi_processor_driver);
 285         if (result < 0)
 286                 return result;
 287
 288         acpi_processor_syscore_init();
 289         register_hotcpu_notifier(&acpi_cpu_notifier);
 290         acpi_thermal_cpufreq_init();
 291         acpi_processor_ppc_init();
 292         acpi_processor_throttling_init();
 293         return 0;
 294 }
 295
 296 static void __exit acpi_processor_driver_exit(void)
 297 {
 298         if (acpi_disabled)
 299                 return;
 300
 301         acpi_processor_ppc_exit();
 302         acpi_thermal_cpufreq_exit();
 303         unregister_hotcpu_notifier(&acpi_cpu_notifier);
 304         acpi_processor_syscore_exit();
 305         driver_unregister(&acpi_processor_driver);
 306 }
 307
 308 module_init(acpi_processor_driver_init);
 309 module_exit(acpi_processor_driver_exit);
 310
 311 MODULE_ALIAS("processor");