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 acpi_processor_power_init(pr); 170 171 acpi_pss_perf_init(pr); 172 173 result = acpi_processor_thermal_init(pr, device); 174 if (result) 175 goto err_power_exit; 176 177 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 178 acpi_processor_notify, device); 179 if (!ACPI_SUCCESS(status)) { 180 result = -ENODEV; 181 goto err_thermal_exit; 182 } 183 pr->flags.previously_online = 1; 184 185 return 0; 186 187 err_thermal_exit: 188 acpi_processor_thermal_exit(pr, device); 189 err_power_exit: 190 acpi_processor_power_exit(pr); 191 return result; 192 } 193 194 static int acpi_processor_stop(struct device *dev) 195 { 196 struct acpi_device *device = ACPI_COMPANION(dev); 197 struct acpi_processor *pr; 198 199 if (!device) 200 return 0; 201 202 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 203 acpi_processor_notify); 204 205 pr = acpi_driver_data(device); 206 if (!pr) 207 return 0; 208 acpi_processor_power_exit(pr); 209 210 acpi_cppc_processor_exit(pr); 211 212 acpi_processor_thermal_exit(pr, device); 213 214 return 0; 215 } 216 217 bool acpi_processor_cpufreq_init; 218 219 static int acpi_processor_notifier(struct notifier_block *nb, 220 unsigned long event, void *data) 221 { 222 struct cpufreq_policy *policy = data; 223 224 if (event == CPUFREQ_CREATE_POLICY) { 225 acpi_thermal_cpufreq_init(policy); 226 acpi_processor_ppc_init(policy); 227 } else if (event == CPUFREQ_REMOVE_POLICY) { 228 acpi_processor_ppc_exit(policy); 229 acpi_thermal_cpufreq_exit(policy); 230 } 231 232 return 0; 233 } 234 235 static struct notifier_block acpi_processor_notifier_block = { 236 .notifier_call = acpi_processor_notifier, 237 }; 238 239 void __weak acpi_processor_init_invariance_cppc(void) 240 { } 241 242 /* 243 * We keep the driver loaded even when ACPI is not running. 244 * This is needed for the powernow-k8 driver, that works even without 245 * ACPI, but needs symbols from this driver 246 */ 247 static enum cpuhp_state hp_online; 248 static int __init acpi_processor_driver_init(void) 249 { 250 int result = 0; 251 252 if (acpi_disabled) 253 return 0; 254 255 if (!cpufreq_register_notifier(&acpi_processor_notifier_block, 256 CPUFREQ_POLICY_NOTIFIER)) { 257 acpi_processor_cpufreq_init = true; 258 acpi_processor_ignore_ppc_init(); 259 } 260 261 result = driver_register(&acpi_processor_driver); 262 if (result < 0) 263 return result; 264 265 acpi_processor_register_idle_driver(); 266 267 result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, 268 "acpi/cpu-drv:online", 269 acpi_soft_cpu_online, NULL); 270 if (result < 0) 271 goto err; 272 hp_online = result; 273 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead", 274 NULL, acpi_soft_cpu_dead); 275 276 acpi_processor_throttling_init(); 277 278 /* 279 * Frequency invariance calculations on AMD platforms can't be run until 280 * after acpi_cppc_processor_probe() has been called for all online CPUs 281 */ 282 acpi_processor_init_invariance_cppc(); 283 284 acpi_idle_rescan_dead_smt_siblings(); 285 286 return 0; 287 err: 288 driver_unregister(&acpi_processor_driver); 289 return result; 290 } 291 292 static void __exit acpi_processor_driver_exit(void) 293 { 294 if (acpi_disabled) 295 return; 296 297 if (acpi_processor_cpufreq_init) { 298 cpufreq_unregister_notifier(&acpi_processor_notifier_block, 299 CPUFREQ_POLICY_NOTIFIER); 300 acpi_processor_cpufreq_init = false; 301 } 302 303 cpuhp_remove_state_nocalls(hp_online); 304 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD); 305 acpi_processor_unregister_idle_driver(); 306 driver_unregister(&acpi_processor_driver); 307 } 308 309 module_init(acpi_processor_driver_init); 310 module_exit(acpi_processor_driver_exit); 311 312 MODULE_ALIAS("processor"); 313