kernel/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 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         action &= ~CPU_TASKS_FROZEN;
 124
 125         /*
 126          * CPU_STARTING and CPU_DYING must not sleep. Return here since
 127          * acpi_bus_get_device() may sleep.
 128          */
 129         if (action == CPU_STARTING || action == CPU_DYING)
 130                 return NOTIFY_DONE;
 131
 132         if (!pr || acpi_bus_get_device(pr->handle, &device))
 133                 return NOTIFY_DONE;
 134
 135         if (action == CPU_ONLINE) {
 136                 /*
 137                  * CPU got physically hotplugged and onlined for the first time:
 138                  * Initialize missing things.
 139                  */
 140                 if (pr->flags.need_hotplug_init) {
 141                         int ret;
 142
 143                         pr_info("Will online and init hotplugged CPU: %d\n",
 144                                 pr->id);
 145                         pr->flags.need_hotplug_init = 0;
 146                         ret = __acpi_processor_start(device);
 147                         WARN(ret, "Failed to start CPU: %d\n", pr->id);
 148                 } else {
 149                         /* Normal CPU soft online event. */
 150                         acpi_processor_ppc_has_changed(pr, 0);
 151                         acpi_processor_hotplug(pr);
 152                         acpi_processor_reevaluate_tstate(pr, action);
 153                         acpi_processor_tstate_has_changed(pr);
 154                 }
 155         } else if (action == CPU_DEAD) {
 156                 /* Invalidate flag.throttling after the CPU is offline. */
 157                 acpi_processor_reevaluate_tstate(pr, action);
 158         }
 159         return NOTIFY_OK;
 160 }
 161
 162 static struct notifier_block __refdata acpi_cpu_notifier = {
 163             .notifier_call = acpi_cpu_soft_notify,
 164 };
 165
 166 static int __acpi_processor_start(struct acpi_device *device)
 167 {
 168         struct acpi_processor *pr = acpi_driver_data(device);
 169         acpi_status status;
 170         int result = 0;
 171
 172         if (!pr)
 173                 return -ENODEV;
 174
 175         if (pr->flags.need_hotplug_init)
 176                 return 0;
 177
 178 #ifdef CONFIG_CPU_FREQ
 179         acpi_processor_ppc_has_changed(pr, 0);
 180 #endif
 181         acpi_processor_get_throttling_info(pr);
 182
 183         if (pr->flags.throttling)
 184                 pr->flags.limit = 1;
 185
 186         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 187                 acpi_processor_power_init(pr);
 188
 189         pr->cdev = thermal_cooling_device_register("Processor", device,
 190                                                    &processor_cooling_ops);
 191         if (IS_ERR(pr->cdev)) {
 192                 result = PTR_ERR(pr->cdev);
 193                 goto err_power_exit;
 194         }
 195
 196         dev_dbg(&device->dev, "registered as cooling_device%d\n",
 197                 pr->cdev->id);
 198
 199         result = sysfs_create_link(&device->dev.kobj,
 200                                    &pr->cdev->device.kobj,
 201                                    "thermal_cooling");
 202         if (result) {
 203                 dev_err(&device->dev,
 204                         "Failed to create sysfs link 'thermal_cooling'\n");
 205                 goto err_thermal_unregister;
 206         }
 207         result = sysfs_create_link(&pr->cdev->device.kobj,
 208                                    &device->dev.kobj,
 209                                    "device");
 210         if (result) {
 211                 dev_err(&pr->cdev->device,
 212                         "Failed to create sysfs link 'device'\n");
 213                 goto err_remove_sysfs_thermal;
 214         }
 215
 216         status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 217                                              acpi_processor_notify, device);
 218         if (ACPI_SUCCESS(status))
 219                 return 0;
 220
 221         sysfs_remove_link(&pr->cdev->device.kobj, "device");
 222  err_remove_sysfs_thermal:
 223         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 224  err_thermal_unregister:
 225         thermal_cooling_device_unregister(pr->cdev);
 226  err_power_exit:
 227         acpi_processor_power_exit(pr);
 228         return result;
 229 }
 230
 231 static int acpi_processor_start(struct device *dev)
 232 {
 233         struct acpi_device *device = ACPI_COMPANION(dev);
 234
 235         if (!device)
 236                 return -ENODEV;
 237
 238         return __acpi_processor_start(device);
 239 }
 240
 241 static int acpi_processor_stop(struct device *dev)
 242 {
 243         struct acpi_device *device = ACPI_COMPANION(dev);
 244         struct acpi_processor *pr;
 245
 246         if (!device)
 247                 return 0;
 248
 249         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 250                                    acpi_processor_notify);
 251
 252         pr = acpi_driver_data(device);
 253         if (!pr)
 254                 return 0;
 255
 256         acpi_processor_power_exit(pr);
 257
 258         if (pr->cdev) {
 259                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 260                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
 261                 thermal_cooling_device_unregister(pr->cdev);
 262                 pr->cdev = NULL;
 263         }
 264         return 0;
 265 }
 266
 267 /*
 268  * We keep the driver loaded even when ACPI is not running.
 269  * This is needed for the powernow-k8 driver, that works even without
 270  * ACPI, but needs symbols from this driver
 271  */
 272
 273 static int __init acpi_processor_driver_init(void)
 274 {
 275         int result = 0;
 276
 277         if (acpi_disabled)
 278                 return 0;
 279
 280         result = driver_register(&acpi_processor_driver);
 281         if (result < 0)
 282                 return result;
 283
 284         acpi_processor_syscore_init();
 285         register_hotcpu_notifier(&acpi_cpu_notifier);
 286         acpi_thermal_cpufreq_init();
 287         acpi_processor_ppc_init();
 288         acpi_processor_throttling_init();
 289         return 0;
 290 }
 291
 292 static void __exit acpi_processor_driver_exit(void)
 293 {
 294         if (acpi_disabled)
 295                 return;
 296
 297         acpi_processor_ppc_exit();
 298         acpi_thermal_cpufreq_exit();
 299         unregister_hotcpu_notifier(&acpi_cpu_notifier);
 300         acpi_processor_syscore_exit();
 301         driver_unregister(&acpi_processor_driver);
 302 }
 303
 304 module_init(acpi_processor_driver_init);
 305 module_exit(acpi_processor_driver_exit);
 306
 307 MODULE_ALIAS("processor");