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