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 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25 */
  26
  27#include <linux/kernel.h>
  28#include <linux/module.h>
  29#include <linux/init.h>
  30#include <linux/cpufreq.h>
  31#include <linux/cpu.h>
  32#include <linux/cpuidle.h>
  33#include <linux/slab.h>
  34#include <linux/acpi.h>
  35
  36#include <acpi/processor.h>
  37
  38#include "internal.h"
  39
  40#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
  41#define ACPI_PROCESSOR_NOTIFY_POWER     0x81
  42#define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
  43
  44#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  45ACPI_MODULE_NAME("processor_driver");
  46
  47MODULE_AUTHOR("Paul Diefenbaugh");
  48MODULE_DESCRIPTION("ACPI Processor Driver");
  49MODULE_LICENSE("GPL");
  50
  51static int acpi_processor_start(struct device *dev);
  52static int acpi_processor_stop(struct device *dev);
  53
  54static const struct acpi_device_id processor_device_ids[] = {
  55        {ACPI_PROCESSOR_OBJECT_HID, 0},
  56        {ACPI_PROCESSOR_DEVICE_HID, 0},
  57        {"", 0},
  58};
  59MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  60
  61static struct device_driver acpi_processor_driver = {
  62        .name = "processor",
  63        .bus = &cpu_subsys,
  64        .acpi_match_table = processor_device_ids,
  65        .probe = acpi_processor_start,
  66        .remove = acpi_processor_stop,
  67};
  68
  69static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
  70{
  71        struct acpi_device *device = data;
  72        struct acpi_processor *pr;
  73        int saved;
  74
  75        if (device->handle != handle)
  76                return;
  77
  78        pr = acpi_driver_data(device);
  79        if (!pr)
  80                return;
  81
  82        switch (event) {
  83        case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
  84                saved = pr->performance_platform_limit;
  85                acpi_processor_ppc_has_changed(pr, 1);
  86                if (saved == pr->performance_platform_limit)
  87                        break;
  88                acpi_bus_generate_netlink_event(device->pnp.device_class,
  89                                                  dev_name(&device->dev), event,
  90                                                  pr->performance_platform_limit);
  91                break;
  92        case ACPI_PROCESSOR_NOTIFY_POWER:
  93                acpi_processor_cst_has_changed(pr);
  94                acpi_bus_generate_netlink_event(device->pnp.device_class,
  95                                                  dev_name(&device->dev), event, 0);
  96                break;
  97        case ACPI_PROCESSOR_NOTIFY_THROTTLING:
  98                acpi_processor_tstate_has_changed(pr);
  99                acpi_bus_generate_netlink_event(device->pnp.device_class,
 100                                                  dev_name(&device->dev), event, 0);
 101                break;
 102        default:
 103                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 104                                  "Unsupported event [0x%x]\n", event));
 105                break;
 106        }
 107
 108        return;
 109}
 110
 111static int __acpi_processor_start(struct acpi_device *device);
 112
 113static int acpi_cpu_soft_notify(struct notifier_block *nfb,
 114                                          unsigned long action, void *hcpu)
 115{
 116        unsigned int cpu = (unsigned long)hcpu;
 117        struct acpi_processor *pr = per_cpu(processors, cpu);
 118        struct acpi_device *device;
 119        action &= ~CPU_TASKS_FROZEN;
 120
 121        /*
 122         * CPU_STARTING and CPU_DYING must not sleep. Return here since
 123         * acpi_bus_get_device() may sleep.
 124         */
 125        if (action == CPU_STARTING || action == CPU_DYING)
 126                return NOTIFY_DONE;
 127
 128        if (!pr || acpi_bus_get_device(pr->handle, &device))
 129                return NOTIFY_DONE;
 130
 131        if (action == CPU_ONLINE) {
 132                /*
 133                 * CPU got physically hotplugged and onlined for the first time:
 134                 * Initialize missing things.
 135                 */
 136                if (pr->flags.need_hotplug_init) {
 137                        int ret;
 138
 139                        pr_info("Will online and init hotplugged CPU: %d\n",
 140                                pr->id);
 141                        pr->flags.need_hotplug_init = 0;
 142                        ret = __acpi_processor_start(device);
 143                        WARN(ret, "Failed to start CPU: %d\n", pr->id);
 144                } else {
 145                        /* Normal CPU soft online event. */
 146                        acpi_processor_ppc_has_changed(pr, 0);
 147                        acpi_processor_hotplug(pr);
 148                        acpi_processor_reevaluate_tstate(pr, action);
 149                        acpi_processor_tstate_has_changed(pr);
 150                }
 151        } else if (action == CPU_DEAD) {
 152                /* Invalidate flag.throttling after the CPU is offline. */
 153                acpi_processor_reevaluate_tstate(pr, action);
 154        }
 155        return NOTIFY_OK;
 156}
 157
 158static struct notifier_block acpi_cpu_notifier = {
 159            .notifier_call = acpi_cpu_soft_notify,
 160};
 161
 162#ifdef CONFIG_ACPI_CPU_FREQ_PSS
 163static int acpi_pss_perf_init(struct acpi_processor *pr,
 164                struct acpi_device *device)
 165{
 166        int result = 0;
 167
 168        acpi_processor_ppc_has_changed(pr, 0);
 169
 170        acpi_processor_get_throttling_info(pr);
 171
 172        if (pr->flags.throttling)
 173                pr->flags.limit = 1;
 174
 175        pr->cdev = thermal_cooling_device_register("Processor", device,
 176                                                   &processor_cooling_ops);
 177        if (IS_ERR(pr->cdev)) {
 178                result = PTR_ERR(pr->cdev);
 179                return result;
 180        }
 181
 182        dev_dbg(&device->dev, "registered as cooling_device%d\n",
 183                pr->cdev->id);
 184
 185        result = sysfs_create_link(&device->dev.kobj,
 186                                   &pr->cdev->device.kobj,
 187                                   "thermal_cooling");
 188        if (result) {
 189                dev_err(&device->dev,
 190                        "Failed to create sysfs link 'thermal_cooling'\n");
 191                goto err_thermal_unregister;
 192        }
 193
 194        result = sysfs_create_link(&pr->cdev->device.kobj,
 195                                   &device->dev.kobj,
 196                                   "device");
 197        if (result) {
 198                dev_err(&pr->cdev->device,
 199                        "Failed to create sysfs link 'device'\n");
 200                goto err_remove_sysfs_thermal;
 201        }
 202
 203        return 0;
 204
 205 err_remove_sysfs_thermal:
 206        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 207 err_thermal_unregister:
 208        thermal_cooling_device_unregister(pr->cdev);
 209
 210        return result;
 211}
 212
 213static void acpi_pss_perf_exit(struct acpi_processor *pr,
 214                struct acpi_device *device)
 215{
 216        if (pr->cdev) {
 217                sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 218                sysfs_remove_link(&pr->cdev->device.kobj, "device");
 219                thermal_cooling_device_unregister(pr->cdev);
 220                pr->cdev = NULL;
 221        }
 222}
 223#else
 224static inline int acpi_pss_perf_init(struct acpi_processor *pr,
 225                struct acpi_device *device)
 226{
 227        return 0;
 228}
 229
 230static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
 231                struct acpi_device *device) {}
 232#endif /* CONFIG_ACPI_CPU_FREQ_PSS */
 233
 234static int __acpi_processor_start(struct acpi_device *device)
 235{
 236        struct acpi_processor *pr = acpi_driver_data(device);
 237        acpi_status status;
 238        int result = 0;
 239
 240        if (!pr)
 241                return -ENODEV;
 242
 243        if (pr->flags.need_hotplug_init)
 244                return 0;
 245
 246        result = acpi_cppc_processor_probe(pr);
 247        if (result)
 248                return -ENODEV;
 249
 250        if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 251                acpi_processor_power_init(pr);
 252
 253        result = acpi_pss_perf_init(pr, device);
 254        if (result)
 255                goto err_power_exit;
 256
 257        status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 258                                             acpi_processor_notify, device);
 259        if (ACPI_SUCCESS(status))
 260                return 0;
 261
 262err_power_exit:
 263        acpi_processor_power_exit(pr);
 264        return result;
 265}
 266
 267static int acpi_processor_start(struct device *dev)
 268{
 269        struct acpi_device *device = ACPI_COMPANION(dev);
 270
 271        if (!device)
 272                return -ENODEV;
 273
 274        return __acpi_processor_start(device);
 275}
 276
 277static int acpi_processor_stop(struct device *dev)
 278{
 279        struct acpi_device *device = ACPI_COMPANION(dev);
 280        struct acpi_processor *pr;
 281
 282        if (!device)
 283                return 0;
 284
 285        acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 286                                   acpi_processor_notify);
 287
 288        pr = acpi_driver_data(device);
 289        if (!pr)
 290                return 0;
 291        acpi_processor_power_exit(pr);
 292
 293        acpi_pss_perf_exit(pr, device);
 294
 295        acpi_cppc_processor_exit(pr);
 296
 297        return 0;
 298}
 299
 300/*
 301 * We keep the driver loaded even when ACPI is not running.
 302 * This is needed for the powernow-k8 driver, that works even without
 303 * ACPI, but needs symbols from this driver
 304 */
 305
 306static int __init acpi_processor_driver_init(void)
 307{
 308        int result = 0;
 309
 310        if (acpi_disabled)
 311                return 0;
 312
 313        result = driver_register(&acpi_processor_driver);
 314        if (result < 0)
 315                return result;
 316
 317        register_hotcpu_notifier(&acpi_cpu_notifier);
 318        acpi_thermal_cpufreq_init();
 319        acpi_processor_ppc_init();
 320        acpi_processor_throttling_init();
 321        return 0;
 322}
 323
 324static void __exit acpi_processor_driver_exit(void)
 325{
 326        if (acpi_disabled)
 327                return;
 328
 329        acpi_processor_ppc_exit();
 330        acpi_thermal_cpufreq_exit();
 331        unregister_hotcpu_notifier(&acpi_cpu_notifier);
 332        driver_unregister(&acpi_processor_driver);
 333}
 334
 335module_init(acpi_processor_driver_init);
 336module_exit(acpi_processor_driver_exit);
 337
 338MODULE_ALIAS("processor");
 339