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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  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
  45 ACPI_MODULE_NAME("processor_driver");
  46
  47 MODULE_AUTHOR("Paul Diefenbaugh");
  48 MODULE_DESCRIPTION("ACPI Processor Driver");
  49 MODULE_LICENSE("GPL");
  50
  51 static int acpi_processor_start(struct device *dev);
  52 static int acpi_processor_stop(struct device *dev);
  53
  54 static const struct acpi_device_id processor_device_ids[] = {
  55         {ACPI_PROCESSOR_OBJECT_HID, 0},
  56         {ACPI_PROCESSOR_DEVICE_HID, 0},
  57         {"", 0},
  58 };
  59 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  60
  61 static 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
  69 static 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
 111 static int __acpi_processor_start(struct acpi_device *device);
 112
 113 static 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
 158 static struct notifier_block acpi_cpu_notifier = {
 159             .notifier_call = acpi_cpu_soft_notify,
 160 };
 161
 162 #ifdef CONFIG_ACPI_CPU_FREQ_PSS
 163 static 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
 213 static 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
 224 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
 225                 struct acpi_device *device)
 226 {
 227         return 0;
 228 }
 229
 230 static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
 231                 struct acpi_device *device) {}
 232 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
 233
 234 static 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
 262         result = -ENODEV;
 263         acpi_pss_perf_exit(pr, device);
 264
 265 err_power_exit:
 266         acpi_processor_power_exit(pr);
 267         return result;
 268 }
 269
 270 static int acpi_processor_start(struct device *dev)
 271 {
 272         struct acpi_device *device = ACPI_COMPANION(dev);
 273         int ret;
 274
 275         if (!device)
 276                 return -ENODEV;
 277
 278         /* Protect against concurrent CPU hotplug operations */
 279         get_online_cpus();
 280         ret = __acpi_processor_start(device);
 281         put_online_cpus();
 282         return ret;
 283 }
 284
 285 static int acpi_processor_stop(struct device *dev)
 286 {
 287         struct acpi_device *device = ACPI_COMPANION(dev);
 288         struct acpi_processor *pr;
 289
 290         if (!device)
 291                 return 0;
 292
 293         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 294                                    acpi_processor_notify);
 295
 296         pr = acpi_driver_data(device);
 297         if (!pr)
 298                 return 0;
 299         acpi_processor_power_exit(pr);
 300
 301         acpi_pss_perf_exit(pr, device);
 302
 303         acpi_cppc_processor_exit(pr);
 304
 305         return 0;
 306 }
 307
 308 /*
 309  * We keep the driver loaded even when ACPI is not running.
 310  * This is needed for the powernow-k8 driver, that works even without
 311  * ACPI, but needs symbols from this driver
 312  */
 313
 314 static int __init acpi_processor_driver_init(void)
 315 {
 316         int result = 0;
 317
 318         if (acpi_disabled)
 319                 return 0;
 320
 321         result = driver_register(&acpi_processor_driver);
 322         if (result < 0)
 323                 return result;
 324
 325         acpi_processor_syscore_init();
 326         register_hotcpu_notifier(&acpi_cpu_notifier);
 327         acpi_thermal_cpufreq_init();
 328         acpi_processor_ppc_init();
 329         acpi_processor_throttling_init();
 330         return 0;
 331 }
 332
 333 static void __exit acpi_processor_driver_exit(void)
 334 {
 335         if (acpi_disabled)
 336                 return;
 337
 338         acpi_processor_ppc_exit();
 339         acpi_thermal_cpufreq_exit();
 340         unregister_hotcpu_notifier(&acpi_cpu_notifier);
 341         acpi_processor_syscore_exit();
 342         driver_unregister(&acpi_processor_driver);
 343 }
 344
 345 module_init(acpi_processor_driver_init);
 346 module_exit(acpi_processor_driver_exit);
 347
 348 MODULE_ALIAS("processor");