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_power_state_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_soft_cpu_online(unsigned int cpu)
 114 {
 115         struct acpi_processor *pr = per_cpu(processors, cpu);
 116         struct acpi_device *device;
 117
 118         if (!pr || acpi_bus_get_device(pr->handle, &device))
 119                 return 0;
 120         /*
 121          * CPU got physically hotplugged and onlined for the first time:
 122          * Initialize missing things.
 123          */
 124         if (pr->flags.need_hotplug_init) {
 125                 int ret;
 126
 127                 pr_info("Will online and init hotplugged CPU: %d\n",
 128                         pr->id);
 129                 pr->flags.need_hotplug_init = 0;
 130                 ret = __acpi_processor_start(device);
 131                 WARN(ret, "Failed to start CPU: %d\n", pr->id);
 132         } else {
 133                 /* Normal CPU soft online event. */
 134                 acpi_processor_ppc_has_changed(pr, 0);
 135                 acpi_processor_hotplug(pr);
 136                 acpi_processor_reevaluate_tstate(pr, false);
 137                 acpi_processor_tstate_has_changed(pr);
 138         }
 139         return 0;
 140 }
 141
 142 static int acpi_soft_cpu_dead(unsigned int cpu)
 143 {
 144         struct acpi_processor *pr = per_cpu(processors, cpu);
 145         struct acpi_device *device;
 146
 147         if (!pr || acpi_bus_get_device(pr->handle, &device))
 148                 return 0;
 149
 150         acpi_processor_reevaluate_tstate(pr, true);
 151         return 0;
 152 }
 153
 154 #ifdef CONFIG_ACPI_CPU_FREQ_PSS
 155 static int acpi_pss_perf_init(struct acpi_processor *pr,
 156                 struct acpi_device *device)
 157 {
 158         int result = 0;
 159
 160         acpi_processor_ppc_has_changed(pr, 0);
 161
 162         acpi_processor_get_throttling_info(pr);
 163
 164         if (pr->flags.throttling)
 165                 pr->flags.limit = 1;
 166
 167         pr->cdev = thermal_cooling_device_register("Processor", device,
 168                                                    &processor_cooling_ops);
 169         if (IS_ERR(pr->cdev)) {
 170                 result = PTR_ERR(pr->cdev);
 171                 return result;
 172         }
 173
 174         dev_dbg(&device->dev, "registered as cooling_device%d\n",
 175                 pr->cdev->id);
 176
 177         result = sysfs_create_link(&device->dev.kobj,
 178                                    &pr->cdev->device.kobj,
 179                                    "thermal_cooling");
 180         if (result) {
 181                 dev_err(&device->dev,
 182                         "Failed to create sysfs link 'thermal_cooling'\n");
 183                 goto err_thermal_unregister;
 184         }
 185
 186         result = sysfs_create_link(&pr->cdev->device.kobj,
 187                                    &device->dev.kobj,
 188                                    "device");
 189         if (result) {
 190                 dev_err(&pr->cdev->device,
 191                         "Failed to create sysfs link 'device'\n");
 192                 goto err_remove_sysfs_thermal;
 193         }
 194
 195         return 0;
 196
 197  err_remove_sysfs_thermal:
 198         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 199  err_thermal_unregister:
 200         thermal_cooling_device_unregister(pr->cdev);
 201
 202         return result;
 203 }
 204
 205 static void acpi_pss_perf_exit(struct acpi_processor *pr,
 206                 struct acpi_device *device)
 207 {
 208         if (pr->cdev) {
 209                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 210                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
 211                 thermal_cooling_device_unregister(pr->cdev);
 212                 pr->cdev = NULL;
 213         }
 214 }
 215 #else
 216 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
 217                 struct acpi_device *device)
 218 {
 219         return 0;
 220 }
 221
 222 static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
 223                 struct acpi_device *device) {}
 224 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
 225
 226 static int __acpi_processor_start(struct acpi_device *device)
 227 {
 228         struct acpi_processor *pr = acpi_driver_data(device);
 229         acpi_status status;
 230         int result = 0;
 231
 232         if (!pr)
 233                 return -ENODEV;
 234
 235         if (pr->flags.need_hotplug_init)
 236                 return 0;
 237
 238         result = acpi_cppc_processor_probe(pr);
 239         if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
 240                 dev_dbg(&device->dev, "CPPC data invalid or not present\n");
 241
 242         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 243                 acpi_processor_power_init(pr);
 244
 245         result = acpi_pss_perf_init(pr, device);
 246         if (result)
 247                 goto err_power_exit;
 248
 249         status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 250                                              acpi_processor_notify, device);
 251         if (ACPI_SUCCESS(status))
 252                 return 0;
 253
 254         result = -ENODEV;
 255         acpi_pss_perf_exit(pr, device);
 256
 257 err_power_exit:
 258         acpi_processor_power_exit(pr);
 259         return result;
 260 }
 261
 262 static int acpi_processor_start(struct device *dev)
 263 {
 264         struct acpi_device *device = ACPI_COMPANION(dev);
 265         int ret;
 266
 267         if (!device)
 268                 return -ENODEV;
 269
 270         /* Protect against concurrent CPU hotplug operations */
 271         cpu_hotplug_disable();
 272         ret = __acpi_processor_start(device);
 273         cpu_hotplug_enable();
 274         return ret;
 275 }
 276
 277 static 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 static enum cpuhp_state hp_online;
 306 static 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         result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
 318                                            "acpi/cpu-drv:online",
 319                                            acpi_soft_cpu_online, NULL);
 320         if (result < 0)
 321                 goto err;
 322         hp_online = result;
 323         cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
 324                                   NULL, acpi_soft_cpu_dead);
 325
 326         acpi_thermal_cpufreq_init();
 327         acpi_processor_ppc_init();
 328         acpi_processor_throttling_init();
 329         return 0;
 330 err:
 331         driver_unregister(&acpi_processor_driver);
 332         return result;
 333 }
 334
 335 static void __exit acpi_processor_driver_exit(void)
 336 {
 337         if (acpi_disabled)
 338                 return;
 339
 340         acpi_processor_ppc_exit();
 341         acpi_thermal_cpufreq_exit();
 342         cpuhp_remove_state_nocalls(hp_online);
 343         cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
 344         driver_unregister(&acpi_processor_driver);
 345 }
 346
 347 module_init(acpi_processor_driver_init);
 348 module_exit(acpi_processor_driver_exit);
 349
 350 MODULE_ALIAS("processor");