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  *  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
  51 ACPI_MODULE_NAME("processor_driver");
  52
  53 MODULE_AUTHOR("Paul Diefenbaugh");
  54 MODULE_DESCRIPTION("ACPI Processor Driver");
  55 MODULE_LICENSE("GPL");
  56
  57 static int acpi_processor_start(struct device *dev);
  58 static int acpi_processor_stop(struct device *dev);
  59
  60 static const struct acpi_device_id processor_device_ids[] = {
  61         {ACPI_PROCESSOR_OBJECT_HID, 0},
  62         {ACPI_PROCESSOR_DEVICE_HID, 0},
  63         {"", 0},
  64 };
  65 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  66
  67 static 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
  75 static 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
 117 static int __acpi_processor_start(struct acpi_device *device);
 118
 119 static 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
 156 static struct notifier_block __refdata acpi_cpu_notifier = {
 157             .notifier_call = acpi_cpu_soft_notify,
 158 };
 159
 160 static int __acpi_processor_start(struct acpi_device *device)
 161 {
 162         struct acpi_processor *pr = acpi_driver_data(device);
 163         acpi_status status;
 164         int result = 0;
 165
 166         if (!pr)
 167                 return -ENODEV;
 168
 169         if (pr->flags.need_hotplug_init)
 170                 return 0;
 171
 172 #ifdef CONFIG_CPU_FREQ
 173         acpi_processor_ppc_has_changed(pr, 0);
 174 #endif
 175         acpi_processor_get_throttling_info(pr);
 176
 177         if (pr->flags.throttling)
 178                 pr->flags.limit = 1;
 179
 180         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 181                 acpi_processor_power_init(pr);
 182
 183         pr->cdev = thermal_cooling_device_register("Processor", device,
 184                                                    &processor_cooling_ops);
 185         if (IS_ERR(pr->cdev)) {
 186                 result = PTR_ERR(pr->cdev);
 187                 goto err_power_exit;
 188         }
 189
 190         dev_dbg(&device->dev, "registered as cooling_device%d\n",
 191                 pr->cdev->id);
 192
 193         result = sysfs_create_link(&device->dev.kobj,
 194                                    &pr->cdev->device.kobj,
 195                                    "thermal_cooling");
 196         if (result) {
 197                 dev_err(&device->dev,
 198                         "Failed to create sysfs link 'thermal_cooling'\n");
 199                 goto err_thermal_unregister;
 200         }
 201         result = sysfs_create_link(&pr->cdev->device.kobj,
 202                                    &device->dev.kobj,
 203                                    "device");
 204         if (result) {
 205                 dev_err(&pr->cdev->device,
 206                         "Failed to create sysfs link 'device'\n");
 207                 goto err_remove_sysfs_thermal;
 208         }
 209
 210         status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 211                                              acpi_processor_notify, device);
 212         if (ACPI_SUCCESS(status))
 213                 return 0;
 214
 215         sysfs_remove_link(&pr->cdev->device.kobj, "device");
 216  err_remove_sysfs_thermal:
 217         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 218  err_thermal_unregister:
 219         thermal_cooling_device_unregister(pr->cdev);
 220  err_power_exit:
 221         acpi_processor_power_exit(pr);
 222         return result;
 223 }
 224
 225 static int acpi_processor_start(struct device *dev)
 226 {
 227         struct acpi_device *device = ACPI_COMPANION(dev);
 228
 229         if (!device)
 230                 return -ENODEV;
 231
 232         return __acpi_processor_start(device);
 233 }
 234
 235 static int acpi_processor_stop(struct device *dev)
 236 {
 237         struct acpi_device *device = ACPI_COMPANION(dev);
 238         struct acpi_processor *pr;
 239
 240         if (!device)
 241                 return 0;
 242
 243         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 244                                    acpi_processor_notify);
 245
 246         pr = acpi_driver_data(device);
 247         if (!pr)
 248                 return 0;
 249
 250         acpi_processor_power_exit(pr);
 251
 252         if (pr->cdev) {
 253                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 254                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
 255                 thermal_cooling_device_unregister(pr->cdev);
 256                 pr->cdev = NULL;
 257         }
 258         return 0;
 259 }
 260
 261 /*
 262  * We keep the driver loaded even when ACPI is not running.
 263  * This is needed for the powernow-k8 driver, that works even without
 264  * ACPI, but needs symbols from this driver
 265  */
 266
 267 static int __init acpi_processor_driver_init(void)
 268 {
 269         int result = 0;
 270
 271         if (acpi_disabled)
 272                 return 0;
 273
 274         result = driver_register(&acpi_processor_driver);
 275         if (result < 0)
 276                 return result;
 277
 278         acpi_processor_syscore_init();
 279         register_hotcpu_notifier(&acpi_cpu_notifier);
 280         acpi_thermal_cpufreq_init();
 281         acpi_processor_ppc_init();
 282         acpi_processor_throttling_init();
 283         return 0;
 284 }
 285
 286 static void __exit acpi_processor_driver_exit(void)
 287 {
 288         if (acpi_disabled)
 289                 return;
 290
 291         acpi_processor_ppc_exit();
 292         acpi_thermal_cpufreq_exit();
 293         unregister_hotcpu_notifier(&acpi_cpu_notifier);
 294         acpi_processor_syscore_exit();
 295         driver_unregister(&acpi_processor_driver);
 296 }
 297
 298 module_init(acpi_processor_driver_init);
 299 module_exit(acpi_processor_driver_exit);
 300
 301 MODULE_ALIAS("processor");