drivers/acpi/processor_driver.c

   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  *  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");