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 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");