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