linux/drivers/acpi/processor_driver.c
<<
>>
Prefs
   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_NOTIFY_PERFORMANCE 0x80
  47#define ACPI_PROCESSOR_NOTIFY_POWER     0x81
  48#define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
  49
  50#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  51ACPI_MODULE_NAME("processor_driver");
  52
  53MODULE_AUTHOR("Paul Diefenbaugh");
  54MODULE_DESCRIPTION("ACPI Processor Driver");
  55MODULE_LICENSE("GPL");
  56
  57static int acpi_processor_start(struct device *dev);
  58static int acpi_processor_stop(struct device *dev);
  59
  60static const struct acpi_device_id processor_device_ids[] = {
  61        {ACPI_PROCESSOR_OBJECT_HID, 0},
  62        {ACPI_PROCESSOR_DEVICE_HID, 0},
  63        {"", 0},
  64};
  65MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  66
  67static 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
  75static 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_netlink_event(device->pnp.device_class,
  95                                                  dev_name(&device->dev), event,
  96                                                  pr->performance_platform_limit);
  97                break;
  98        case ACPI_PROCESSOR_NOTIFY_POWER:
  99                acpi_processor_cst_has_changed(pr);
 100                acpi_bus_generate_netlink_event(device->pnp.device_class,
 101                                                  dev_name(&device->dev), event, 0);
 102                break;
 103        case ACPI_PROCESSOR_NOTIFY_THROTTLING:
 104                acpi_processor_tstate_has_changed(pr);
 105                acpi_bus_generate_netlink_event(device->pnp.device_class,
 106                                                  dev_name(&device->dev), event, 0);
 107                break;
 108        default:
 109                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 110                                  "Unsupported event [0x%x]\n", event));
 111                break;
 112        }
 113
 114        return;
 115}
 116
 117static int __acpi_processor_start(struct acpi_device *device);
 118
 119static int acpi_cpu_soft_notify(struct notifier_block *nfb,
 120                                          unsigned long action, void *hcpu)
 121{
 122        unsigned int cpu = (unsigned long)hcpu;
 123        struct acpi_processor *pr = per_cpu(processors, cpu);
 124        struct acpi_device *device;
 125
 126        if (!pr || acpi_bus_get_device(pr->handle, &device))
 127                return NOTIFY_DONE;
 128
 129        if (action == CPU_ONLINE) {
 130                /*
 131                 * CPU got physically hotplugged and onlined for the first time:
 132                 * Initialize missing things.
 133                 */
 134                if (pr->flags.need_hotplug_init) {
 135                        int ret;
 136
 137                        pr_info("Will online and init hotplugged CPU: %d\n",
 138                                pr->id);
 139                        pr->flags.need_hotplug_init = 0;
 140                        ret = __acpi_processor_start(device);
 141                        WARN(ret, "Failed to start CPU: %d\n", pr->id);
 142                } else {
 143                        /* Normal CPU soft online event. */
 144                        acpi_processor_ppc_has_changed(pr, 0);
 145                        acpi_processor_hotplug(pr);
 146                        acpi_processor_reevaluate_tstate(pr, action);
 147                        acpi_processor_tstate_has_changed(pr);
 148                }
 149        } else if (action == CPU_DEAD) {
 150                /* Invalidate flag.throttling after the CPU is offline. */
 151                acpi_processor_reevaluate_tstate(pr, action);
 152        }
 153        return NOTIFY_OK;
 154}
 155
 156static struct notifier_block __refdata acpi_cpu_notifier =
 157{
 158            .notifier_call = acpi_cpu_soft_notify,
 159};
 160
 161static int __acpi_processor_start(struct acpi_device *device)
 162{
 163        struct acpi_processor *pr = acpi_driver_data(device);
 164        acpi_status status;
 165        int result = 0;
 166
 167        if (!pr)
 168                return -ENODEV;
 169
 170        if (pr->flags.need_hotplug_init)
 171                return 0;
 172
 173#ifdef CONFIG_CPU_FREQ
 174        acpi_processor_ppc_has_changed(pr, 0);
 175        acpi_processor_load_module(pr);
 176#endif
 177        acpi_processor_get_throttling_info(pr);
 178
 179        if (pr->flags.throttling)
 180                pr->flags.limit = 1;
 181
 182        if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 183                acpi_processor_power_init(pr);
 184
 185        pr->cdev = thermal_cooling_device_register("Processor", device,
 186                                                   &processor_cooling_ops);
 187        if (IS_ERR(pr->cdev)) {
 188                result = PTR_ERR(pr->cdev);
 189                goto err_power_exit;
 190        }
 191
 192        dev_dbg(&device->dev, "registered as cooling_device%d\n",
 193                pr->cdev->id);
 194
 195        result = sysfs_create_link(&device->dev.kobj,
 196                                   &pr->cdev->device.kobj,
 197                                   "thermal_cooling");
 198        if (result) {
 199                dev_err(&device->dev,
 200                        "Failed to create sysfs link 'thermal_cooling'\n");
 201                goto err_thermal_unregister;
 202        }
 203        result = sysfs_create_link(&pr->cdev->device.kobj,
 204                                   &device->dev.kobj,
 205                                   "device");
 206        if (result) {
 207                dev_err(&pr->cdev->device,
 208                        "Failed to create sysfs link 'device'\n");
 209                goto err_remove_sysfs_thermal;
 210        }
 211
 212        status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 213                                             acpi_processor_notify, device);
 214        if (ACPI_SUCCESS(status))
 215                return 0;
 216
 217        sysfs_remove_link(&pr->cdev->device.kobj, "device");
 218 err_remove_sysfs_thermal:
 219        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 220 err_thermal_unregister:
 221        thermal_cooling_device_unregister(pr->cdev);
 222 err_power_exit:
 223        acpi_processor_power_exit(pr);
 224        return result;
 225}
 226
 227static int acpi_processor_start(struct device *dev)
 228{
 229        struct acpi_device *device;
 230
 231        if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
 232                return -ENODEV;
 233
 234        return __acpi_processor_start(device);
 235}
 236
 237static int acpi_processor_stop(struct device *dev)
 238{
 239        struct acpi_device *device;
 240        struct acpi_processor *pr;
 241
 242        if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
 243                return 0;
 244
 245        acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 246                                   acpi_processor_notify);
 247
 248        pr = acpi_driver_data(device);
 249        if (!pr)
 250                return 0;
 251
 252        acpi_processor_power_exit(pr);
 253
 254        if (pr->cdev) {
 255                sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 256                sysfs_remove_link(&pr->cdev->device.kobj, "device");
 257                thermal_cooling_device_unregister(pr->cdev);
 258                pr->cdev = NULL;
 259        }
 260        return 0;
 261}
 262
 263/*
 264 * We keep the driver loaded even when ACPI is not running.
 265 * This is needed for the powernow-k8 driver, that works even without
 266 * ACPI, but needs symbols from this driver
 267 */
 268
 269static int __init acpi_processor_driver_init(void)
 270{
 271        int result = 0;
 272
 273        if (acpi_disabled)
 274                return 0;
 275
 276        result = driver_register(&acpi_processor_driver);
 277        if (result < 0)
 278                return result;
 279
 280        acpi_processor_syscore_init();
 281        register_hotcpu_notifier(&acpi_cpu_notifier);
 282        acpi_thermal_cpufreq_init();
 283        acpi_processor_ppc_init();
 284        acpi_processor_throttling_init();
 285        return 0;
 286}
 287
 288static void __exit acpi_processor_driver_exit(void)
 289{
 290        if (acpi_disabled)
 291                return;
 292
 293        acpi_processor_ppc_exit();
 294        acpi_thermal_cpufreq_exit();
 295        unregister_hotcpu_notifier(&acpi_cpu_notifier);
 296        acpi_processor_syscore_exit();
 297        driver_unregister(&acpi_processor_driver);
 298}
 299
 300module_init(acpi_processor_driver_init);
 301module_exit(acpi_processor_driver_exit);
 302
 303MODULE_ALIAS("processor");
 304
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.