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 #define ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED       0x85
  31
  32 MODULE_AUTHOR("Paul Diefenbaugh");
  33 MODULE_DESCRIPTION("ACPI Processor Driver");
  34 MODULE_LICENSE("GPL");
  35
  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         .remove = acpi_processor_stop,
  50 };
  51
  52 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
  53 {
  54         struct acpi_device *device = data;
  55         struct acpi_processor *pr;
  56         int saved;
  57
  58         if (device->handle != handle)
  59                 return;
  60
  61         pr = acpi_driver_data(device);
  62         if (!pr)
  63                 return;
  64
  65         switch (event) {
  66         case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
  67                 saved = pr->performance_platform_limit;
  68                 acpi_processor_ppc_has_changed(pr, 1);
  69                 if (saved == pr->performance_platform_limit)
  70                         break;
  71                 acpi_bus_generate_netlink_event(device->pnp.device_class,
  72                                                   dev_name(&device->dev), event,
  73                                                   pr->performance_platform_limit);
  74                 break;
  75         case ACPI_PROCESSOR_NOTIFY_POWER:
  76                 acpi_processor_power_state_has_changed(pr);
  77                 acpi_bus_generate_netlink_event(device->pnp.device_class,
  78                                                   dev_name(&device->dev), event, 0);
  79                 break;
  80         case ACPI_PROCESSOR_NOTIFY_THROTTLING:
  81                 acpi_processor_tstate_has_changed(pr);
  82                 acpi_bus_generate_netlink_event(device->pnp.device_class,
  83                                                   dev_name(&device->dev), event, 0);
  84                 break;
  85         case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED:
  86                 cpufreq_update_limits(pr->id);
  87                 acpi_bus_generate_netlink_event(device->pnp.device_class,
  88                                                   dev_name(&device->dev), event, 0);
  89                 break;
  90         default:
  91                 acpi_handle_debug(handle, "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)
 106                 return 0;
 107
 108         device = acpi_fetch_acpi_dev(pr->handle);
 109         if (!device)
 110                 return 0;
 111
 112         /*
 113          * CPU got physically hotplugged and onlined for the first time:
 114          * Initialize missing things.
 115          */
 116         if (!pr->flags.previously_online) {
 117                 int ret;
 118
 119                 ret = __acpi_processor_start(device);
 120                 WARN(ret, "Failed to start CPU: %d\n", pr->id);
 121         } else {
 122                 /* Normal CPU soft online event. */
 123                 acpi_processor_ppc_has_changed(pr, 0);
 124                 acpi_processor_hotplug(pr);
 125                 acpi_processor_reevaluate_tstate(pr, false);
 126                 acpi_processor_tstate_has_changed(pr);
 127         }
 128         return 0;
 129 }
 130
 131 static int acpi_soft_cpu_dead(unsigned int cpu)
 132 {
 133         struct acpi_processor *pr = per_cpu(processors, cpu);
 134
 135         if (!pr || !acpi_fetch_acpi_dev(pr->handle))
 136                 return 0;
 137
 138         acpi_processor_reevaluate_tstate(pr, true);
 139         return 0;
 140 }
 141
 142 #ifdef CONFIG_ACPI_CPU_FREQ_PSS
 143 static void acpi_pss_perf_init(struct acpi_processor *pr)
 144 {
 145         acpi_processor_ppc_has_changed(pr, 0);
 146
 147         acpi_processor_get_throttling_info(pr);
 148
 149         if (pr->flags.throttling)
 150                 pr->flags.limit = 1;
 151 }
 152 #else
 153 static inline void acpi_pss_perf_init(struct acpi_processor *pr) {}
 154 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
 155
 156 static int __acpi_processor_start(struct acpi_device *device)
 157 {
 158         struct acpi_processor *pr = acpi_driver_data(device);
 159         acpi_status status;
 160         int result = 0;
 161
 162         if (!pr)
 163                 return -ENODEV;
 164
 165         result = acpi_cppc_processor_probe(pr);
 166         if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
 167                 dev_dbg(&device->dev, "CPPC data invalid or not present\n");
 168
 169         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 170                 acpi_processor_power_init(pr);
 171
 172         acpi_pss_perf_init(pr);
 173
 174         result = acpi_processor_thermal_init(pr, device);
 175         if (result)
 176                 goto err_power_exit;
 177
 178         status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 179                                              acpi_processor_notify, device);
 180         if (!ACPI_SUCCESS(status)) {
 181                 result = -ENODEV;
 182                 goto err_thermal_exit;
 183         }
 184         pr->flags.previously_online = 1;
 185
 186         return 0;
 187
 188 err_thermal_exit:
 189         acpi_processor_thermal_exit(pr, device);
 190 err_power_exit:
 191         acpi_processor_power_exit(pr);
 192         return result;
 193 }
 194
 195 static int acpi_processor_stop(struct device *dev)
 196 {
 197         struct acpi_device *device = ACPI_COMPANION(dev);
 198         struct acpi_processor *pr;
 199
 200         if (!device)
 201                 return 0;
 202
 203         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 204                                    acpi_processor_notify);
 205
 206         pr = acpi_driver_data(device);
 207         if (!pr)
 208                 return 0;
 209         acpi_processor_power_exit(pr);
 210
 211         acpi_cppc_processor_exit(pr);
 212
 213         acpi_processor_thermal_exit(pr, device);
 214
 215         return 0;
 216 }
 217
 218 bool acpi_processor_cpufreq_init;
 219
 220 static int acpi_processor_notifier(struct notifier_block *nb,
 221                                    unsigned long event, void *data)
 222 {
 223         struct cpufreq_policy *policy = data;
 224
 225         if (event == CPUFREQ_CREATE_POLICY) {
 226                 acpi_thermal_cpufreq_init(policy);
 227                 acpi_processor_ppc_init(policy);
 228         } else if (event == CPUFREQ_REMOVE_POLICY) {
 229                 acpi_processor_ppc_exit(policy);
 230                 acpi_thermal_cpufreq_exit(policy);
 231         }
 232
 233         return 0;
 234 }
 235
 236 static struct notifier_block acpi_processor_notifier_block = {
 237         .notifier_call = acpi_processor_notifier,
 238 };
 239
 240 void __weak acpi_processor_init_invariance_cppc(void)
 241 { }
 242
 243 /*
 244  * We keep the driver loaded even when ACPI is not running.
 245  * This is needed for the powernow-k8 driver, that works even without
 246  * ACPI, but needs symbols from this driver
 247  */
 248 static enum cpuhp_state hp_online;
 249 static int __init acpi_processor_driver_init(void)
 250 {
 251         int result = 0;
 252
 253         if (acpi_disabled)
 254                 return 0;
 255
 256         if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
 257                                        CPUFREQ_POLICY_NOTIFIER)) {
 258                 acpi_processor_cpufreq_init = true;
 259                 acpi_processor_ignore_ppc_init();
 260         }
 261
 262         result = driver_register(&acpi_processor_driver);
 263         if (result < 0)
 264                 return result;
 265
 266         result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
 267                                    "acpi/cpu-drv:online",
 268                                    acpi_soft_cpu_online, NULL);
 269         if (result < 0)
 270                 goto err;
 271         hp_online = result;
 272         cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
 273                                   NULL, acpi_soft_cpu_dead);
 274
 275         acpi_processor_throttling_init();
 276
 277         /*
 278          * Frequency invariance calculations on AMD platforms can't be run until
 279          * after acpi_cppc_processor_probe() has been called for all online CPUs
 280          */
 281         acpi_processor_init_invariance_cppc();
 282         return 0;
 283 err:
 284         driver_unregister(&acpi_processor_driver);
 285         return result;
 286 }
 287
 288 static void __exit acpi_processor_driver_exit(void)
 289 {
 290         if (acpi_disabled)
 291                 return;
 292
 293         if (acpi_processor_cpufreq_init) {
 294                 cpufreq_unregister_notifier(&acpi_processor_notifier_block,
 295                                             CPUFREQ_POLICY_NOTIFIER);
 296                 acpi_processor_cpufreq_init = false;
 297         }
 298
 299         cpuhp_remove_state_nocalls(hp_online);
 300         cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
 301         driver_unregister(&acpi_processor_driver);
 302 }
 303
 304 module_init(acpi_processor_driver_init);
 305 module_exit(acpi_processor_driver_exit);
 306
 307 MODULE_ALIAS("processor");