linux/drivers/acpi/processor_driver.c
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   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_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
 121static int __acpi_processor_start(struct acpi_device *device);
 122
 123static 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
 160static struct notifier_block __refdata acpi_cpu_notifier =
 161{
 162            .notifier_call = acpi_cpu_soft_notify,
 163};
 164
 165static 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
 229static 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
 239static 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
 271static 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
 290static 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
 302module_init(acpi_processor_driver_init);
 303module_exit(acpi_processor_driver_exit);
 304
 305MODULE_ALIAS("processor");
 306
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