drivers/acpi/processor_driver.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * processor_driver.c - ACPI Processor Driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   9  *                      - Added processor hotplug support
  10  *  Copyright (C) 2013, Intel Corporation
  11  *                      Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/cpufreq.h>
  18 #include <linux/cpu.h>
  19 #include <linux/cpuidle.h>
  20 #include <linux/slab.h>
  21 #include <linux/acpi.h>
  22
  23 #include <acpi/processor.h>
  24
  25 #include "internal.h"
  26
  27 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
  28 #define ACPI_PROCESSOR_NOTIFY_POWER     0x81
  29 #define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
  30
  31 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  32 ACPI_MODULE_NAME("processor_driver");
  33
  34 MODULE_AUTHOR("Paul Diefenbaugh");
  35 MODULE_DESCRIPTION("ACPI Processor Driver");
  36 MODULE_LICENSE("GPL");
  37
  38 static int acpi_processor_start(struct device *dev);
  39 static int acpi_processor_stop(struct device *dev);
  40
  41 static const struct acpi_device_id processor_device_ids[] = {
  42         {ACPI_PROCESSOR_OBJECT_HID, 0},
  43         {ACPI_PROCESSOR_DEVICE_HID, 0},
  44         {"", 0},
  45 };
  46 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  47
  48 static struct device_driver acpi_processor_driver = {
  49         .name = "processor",
  50         .bus = &cpu_subsys,
  51         .acpi_match_table = processor_device_ids,
  52         .probe = acpi_processor_start,
  53         .remove = acpi_processor_stop,
  54 };
  55
  56 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
  57 {
  58         struct acpi_device *device = data;
  59         struct acpi_processor *pr;
  60         int saved;
  61
  62         if (device->handle != handle)
  63                 return;
  64
  65         pr = acpi_driver_data(device);
  66         if (!pr)
  67                 return;
  68
  69         switch (event) {
  70         case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
  71                 saved = pr->performance_platform_limit;
  72                 acpi_processor_ppc_has_changed(pr, 1);
  73                 if (saved == pr->performance_platform_limit)
  74                         break;
  75                 acpi_bus_generate_netlink_event(device->pnp.device_class,
  76                                                   dev_name(&device->dev), event,
  77                                                   pr->performance_platform_limit);
  78                 break;
  79         case ACPI_PROCESSOR_NOTIFY_POWER:
  80                 acpi_processor_power_state_has_changed(pr);
  81                 acpi_bus_generate_netlink_event(device->pnp.device_class,
  82                                                   dev_name(&device->dev), event, 0);
  83                 break;
  84         case ACPI_PROCESSOR_NOTIFY_THROTTLING:
  85                 acpi_processor_tstate_has_changed(pr);
  86                 acpi_bus_generate_netlink_event(device->pnp.device_class,
  87                                                   dev_name(&device->dev), event, 0);
  88                 break;
  89         default:
  90                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  91                                   "Unsupported event [0x%x]\n", event));
  92                 break;
  93         }
  94
  95         return;
  96 }
  97
  98 static int __acpi_processor_start(struct acpi_device *device);
  99
 100 static int acpi_soft_cpu_online(unsigned int cpu)
 101 {
 102         struct acpi_processor *pr = per_cpu(processors, cpu);
 103         struct acpi_device *device;
 104
 105         if (!pr || acpi_bus_get_device(pr->handle, &device))
 106                 return 0;
 107         /*
 108          * CPU got physically hotplugged and onlined for the first time:
 109          * Initialize missing things.
 110          */
 111         if (pr->flags.need_hotplug_init) {
 112                 int ret;
 113
 114                 pr_info("Will online and init hotplugged CPU: %d\n",
 115                         pr->id);
 116                 pr->flags.need_hotplug_init = 0;
 117                 ret = __acpi_processor_start(device);
 118                 WARN(ret, "Failed to start CPU: %d\n", pr->id);
 119         } else {
 120                 /* Normal CPU soft online event. */
 121                 acpi_processor_ppc_has_changed(pr, 0);
 122                 acpi_processor_hotplug(pr);
 123                 acpi_processor_reevaluate_tstate(pr, false);
 124                 acpi_processor_tstate_has_changed(pr);
 125         }
 126         return 0;
 127 }
 128
 129 static int acpi_soft_cpu_dead(unsigned int cpu)
 130 {
 131         struct acpi_processor *pr = per_cpu(processors, cpu);
 132         struct acpi_device *device;
 133
 134         if (!pr || acpi_bus_get_device(pr->handle, &device))
 135                 return 0;
 136
 137         acpi_processor_reevaluate_tstate(pr, true);
 138         return 0;
 139 }
 140
 141 #ifdef CONFIG_ACPI_CPU_FREQ_PSS
 142 static int acpi_pss_perf_init(struct acpi_processor *pr,
 143                 struct acpi_device *device)
 144 {
 145         int result = 0;
 146
 147         acpi_processor_ppc_has_changed(pr, 0);
 148
 149         acpi_processor_get_throttling_info(pr);
 150
 151         if (pr->flags.throttling)
 152                 pr->flags.limit = 1;
 153
 154         pr->cdev = thermal_cooling_device_register("Processor", device,
 155                                                    &processor_cooling_ops);
 156         if (IS_ERR(pr->cdev)) {
 157                 result = PTR_ERR(pr->cdev);
 158                 return result;
 159         }
 160
 161         dev_dbg(&device->dev, "registered as cooling_device%d\n",
 162                 pr->cdev->id);
 163
 164         result = sysfs_create_link(&device->dev.kobj,
 165                                    &pr->cdev->device.kobj,
 166                                    "thermal_cooling");
 167         if (result) {
 168                 dev_err(&device->dev,
 169                         "Failed to create sysfs link 'thermal_cooling'\n");
 170                 goto err_thermal_unregister;
 171         }
 172
 173         result = sysfs_create_link(&pr->cdev->device.kobj,
 174                                    &device->dev.kobj,
 175                                    "device");
 176         if (result) {
 177                 dev_err(&pr->cdev->device,
 178                         "Failed to create sysfs link 'device'\n");
 179                 goto err_remove_sysfs_thermal;
 180         }
 181
 182         return 0;
 183
 184  err_remove_sysfs_thermal:
 185         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 186  err_thermal_unregister:
 187         thermal_cooling_device_unregister(pr->cdev);
 188
 189         return result;
 190 }
 191
 192 static void acpi_pss_perf_exit(struct acpi_processor *pr,
 193                 struct acpi_device *device)
 194 {
 195         if (pr->cdev) {
 196                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 197                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
 198                 thermal_cooling_device_unregister(pr->cdev);
 199                 pr->cdev = NULL;
 200         }
 201 }
 202 #else
 203 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
 204                 struct acpi_device *device)
 205 {
 206         return 0;
 207 }
 208
 209 static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
 210                 struct acpi_device *device) {}
 211 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
 212
 213 static int __acpi_processor_start(struct acpi_device *device)
 214 {
 215         struct acpi_processor *pr = acpi_driver_data(device);
 216         acpi_status status;
 217         int result = 0;
 218
 219         if (!pr)
 220                 return -ENODEV;
 221
 222         if (pr->flags.need_hotplug_init)
 223                 return 0;
 224
 225         result = acpi_cppc_processor_probe(pr);
 226         if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
 227                 dev_dbg(&device->dev, "CPPC data invalid or not present\n");
 228
 229         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 230                 acpi_processor_power_init(pr);
 231
 232         result = acpi_pss_perf_init(pr, device);
 233         if (result)
 234                 goto err_power_exit;
 235
 236         status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 237                                              acpi_processor_notify, device);
 238         if (ACPI_SUCCESS(status))
 239                 return 0;
 240
 241         result = -ENODEV;
 242         acpi_pss_perf_exit(pr, device);
 243
 244 err_power_exit:
 245         acpi_processor_power_exit(pr);
 246         return result;
 247 }
 248
 249 static int acpi_processor_start(struct device *dev)
 250 {
 251         struct acpi_device *device = ACPI_COMPANION(dev);
 252         int ret;
 253
 254         if (!device)
 255                 return -ENODEV;
 256
 257         /* Protect against concurrent CPU hotplug operations */
 258         cpu_hotplug_disable();
 259         ret = __acpi_processor_start(device);
 260         cpu_hotplug_enable();
 261         return ret;
 262 }
 263
 264 static int acpi_processor_stop(struct device *dev)
 265 {
 266         struct acpi_device *device = ACPI_COMPANION(dev);
 267         struct acpi_processor *pr;
 268
 269         if (!device)
 270                 return 0;
 271
 272         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 273                                    acpi_processor_notify);
 274
 275         pr = acpi_driver_data(device);
 276         if (!pr)
 277                 return 0;
 278         acpi_processor_power_exit(pr);
 279
 280         acpi_pss_perf_exit(pr, device);
 281
 282         acpi_cppc_processor_exit(pr);
 283
 284         return 0;
 285 }
 286
 287 bool acpi_processor_cpufreq_init;
 288
 289 static int acpi_processor_notifier(struct notifier_block *nb,
 290                                    unsigned long event, void *data)
 291 {
 292         struct cpufreq_policy *policy = data;
 293         int cpu = policy->cpu;
 294
 295         if (event == CPUFREQ_CREATE_POLICY) {
 296                 acpi_thermal_cpufreq_init(cpu);
 297                 acpi_processor_ppc_init(cpu);
 298         } else if (event == CPUFREQ_REMOVE_POLICY) {
 299                 acpi_processor_ppc_exit(cpu);
 300                 acpi_thermal_cpufreq_exit(cpu);
 301         }
 302
 303         return 0;
 304 }
 305
 306 static struct notifier_block acpi_processor_notifier_block = {
 307         .notifier_call = acpi_processor_notifier,
 308 };
 309
 310 /*
 311  * We keep the driver loaded even when ACPI is not running.
 312  * This is needed for the powernow-k8 driver, that works even without
 313  * ACPI, but needs symbols from this driver
 314  */
 315 static enum cpuhp_state hp_online;
 316 static int __init acpi_processor_driver_init(void)
 317 {
 318         int result = 0;
 319
 320         if (acpi_disabled)
 321                 return 0;
 322
 323         result = driver_register(&acpi_processor_driver);
 324         if (result < 0)
 325                 return result;
 326
 327         result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
 328                                            "acpi/cpu-drv:online",
 329                                            acpi_soft_cpu_online, NULL);
 330         if (result < 0)
 331                 goto err;
 332         hp_online = result;
 333         cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
 334                                   NULL, acpi_soft_cpu_dead);
 335
 336         if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
 337                                        CPUFREQ_POLICY_NOTIFIER)) {
 338                 acpi_processor_cpufreq_init = true;
 339                 acpi_processor_ignore_ppc_init();
 340         }
 341
 342         acpi_processor_throttling_init();
 343         return 0;
 344 err:
 345         driver_unregister(&acpi_processor_driver);
 346         return result;
 347 }
 348
 349 static void __exit acpi_processor_driver_exit(void)
 350 {
 351         if (acpi_disabled)
 352                 return;
 353
 354         if (acpi_processor_cpufreq_init) {
 355                 cpufreq_unregister_notifier(&acpi_processor_notifier_block,
 356                                             CPUFREQ_POLICY_NOTIFIER);
 357                 acpi_processor_cpufreq_init = false;
 358         }
 359
 360         cpuhp_remove_state_nocalls(hp_online);
 361         cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
 362         driver_unregister(&acpi_processor_driver);
 363 }
 364
 365 module_init(acpi_processor_driver_init);
 366 module_exit(acpi_processor_driver_exit);
 367
 368 MODULE_ALIAS("processor");