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, ev_data = 0; 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 ev_data = pr->performance_platform_limit; 70 if (saved == ev_data) 71 return; 72 73 break; 74 case ACPI_PROCESSOR_NOTIFY_POWER: 75 acpi_processor_power_state_has_changed(pr); 76 break; 77 case ACPI_PROCESSOR_NOTIFY_THROTTLING: 78 acpi_processor_tstate_has_changed(pr); 79 break; 80 case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED: 81 cpufreq_update_limits(pr->id); 82 break; 83 default: 84 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event); 85 return; 86 } 87 88 acpi_bus_generate_netlink_event("processor", dev_name(&device->dev), 89 event, ev_data); 90 } 91 92 static int __acpi_processor_start(struct acpi_device *device); 93 94 static int acpi_soft_cpu_online(unsigned int cpu) 95 { 96 struct acpi_processor *pr = per_cpu(processors, cpu); 97 struct acpi_device *device; 98 99 if (!pr) 100 return 0; 101 102 device = acpi_fetch_acpi_dev(pr->handle); 103 if (!device) 104 return 0; 105 106 /* 107 * CPU got physically hotplugged and onlined for the first time: 108 * Initialize missing things. 109 */ 110 if (!pr->flags.previously_online) { 111 int ret; 112 113 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); 128 129 if (!pr || !acpi_fetch_acpi_dev(pr->handle)) 130 return 0; 131 132 acpi_processor_reevaluate_tstate(pr, true); 133 return 0; 134 } 135 136 #ifdef CONFIG_ACPI_CPU_FREQ_PSS 137 static void acpi_pss_perf_init(struct acpi_processor *pr) 138 { 139 acpi_processor_ppc_has_changed(pr, 0); 140 141 acpi_processor_get_throttling_info(pr); 142 143 if (pr->flags.throttling) 144 pr->flags.limit = 1; 145 } 146 #else 147 static inline void acpi_pss_perf_init(struct acpi_processor *pr) {} 148 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */ 149 150 static int __acpi_processor_start(struct acpi_device *device) 151 { 152 struct acpi_processor *pr = acpi_driver_data(device); 153 acpi_status status; 154 int result = 0; 155 156 if (!pr) 157 return -ENODEV; 158 159 result = acpi_cppc_processor_probe(pr); 160 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS)) 161 dev_dbg(&device->dev, "CPPC data invalid or not present\n"); 162 163 acpi_processor_power_init(pr); 164 165 acpi_pss_perf_init(pr); 166 167 result = acpi_processor_thermal_init(pr, device); 168 if (result) 169 goto err_power_exit; 170 171 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 172 acpi_processor_notify, device); 173 if (!ACPI_SUCCESS(status)) { 174 result = -ENODEV; 175 goto err_thermal_exit; 176 } 177 pr->flags.previously_online = 1; 178 179 return 0; 180 181 err_thermal_exit: 182 acpi_processor_thermal_exit(pr, device); 183 err_power_exit: 184 acpi_processor_power_exit(pr); 185 return result; 186 } 187 188 static int acpi_processor_stop(struct device *dev) 189 { 190 struct acpi_device *device = ACPI_COMPANION(dev); 191 struct acpi_processor *pr; 192 193 if (!device) 194 return 0; 195 196 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 197 acpi_processor_notify); 198 199 pr = acpi_driver_data(device); 200 if (!pr) 201 return 0; 202 acpi_processor_power_exit(pr); 203 204 acpi_cppc_processor_exit(pr); 205 206 acpi_processor_thermal_exit(pr, device); 207 208 return 0; 209 } 210 211 bool acpi_processor_cpufreq_init; 212 213 static int acpi_processor_notifier(struct notifier_block *nb, 214 unsigned long event, void *data) 215 { 216 struct cpufreq_policy *policy = data; 217 218 if (event == CPUFREQ_CREATE_POLICY) { 219 acpi_thermal_cpufreq_init(policy); 220 acpi_processor_ppc_init(policy); 221 } else if (event == CPUFREQ_REMOVE_POLICY) { 222 acpi_processor_ppc_exit(policy); 223 acpi_thermal_cpufreq_exit(policy); 224 } 225 226 return 0; 227 } 228 229 static struct notifier_block acpi_processor_notifier_block = { 230 .notifier_call = acpi_processor_notifier, 231 }; 232 233 void __weak acpi_processor_init_invariance_cppc(void) 234 { } 235 236 /* 237 * We keep the driver loaded even when ACPI is not running. 238 * This is needed for the powernow-k8 driver, that works even without 239 * ACPI, but needs symbols from this driver 240 */ 241 static enum cpuhp_state hp_online; 242 static int __init acpi_processor_driver_init(void) 243 { 244 int result = 0; 245 246 if (acpi_disabled) 247 return 0; 248 249 if (!cpufreq_register_notifier(&acpi_processor_notifier_block, 250 CPUFREQ_POLICY_NOTIFIER)) { 251 acpi_processor_cpufreq_init = true; 252 acpi_processor_ignore_ppc_init(); 253 } 254 255 acpi_processor_register_idle_driver(); 256 257 result = driver_register(&acpi_processor_driver); 258 if (result < 0) 259 goto unregister_idle_drv; 260 261 result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, 262 "acpi/cpu-drv:online", 263 acpi_soft_cpu_online, NULL); 264 if (result < 0) 265 goto err; 266 hp_online = result; 267 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead", 268 NULL, acpi_soft_cpu_dead); 269 270 acpi_processor_throttling_init(); 271 272 /* 273 * Frequency invariance calculations on AMD platforms can't be run until 274 * after acpi_cppc_processor_probe() has been called for all online CPUs 275 */ 276 acpi_processor_init_invariance_cppc(); 277 278 acpi_idle_rescan_dead_smt_siblings(); 279 280 return 0; 281 282 err: 283 driver_unregister(&acpi_processor_driver); 284 285 unregister_idle_drv: 286 acpi_processor_unregister_idle_driver(); 287 288 return result; 289 } 290 291 static void __exit acpi_processor_driver_exit(void) 292 { 293 if (acpi_disabled) 294 return; 295 296 if (acpi_processor_cpufreq_init) { 297 cpufreq_unregister_notifier(&acpi_processor_notifier_block, 298 CPUFREQ_POLICY_NOTIFIER); 299 acpi_processor_cpufreq_init = false; 300 } 301 302 cpuhp_remove_state_nocalls(hp_online); 303 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD); 304 driver_unregister(&acpi_processor_driver); 305 acpi_processor_unregister_idle_driver(); 306 } 307 308 module_init(acpi_processor_driver_init); 309 module_exit(acpi_processor_driver_exit); 310 311 MODULE_ALIAS("processor"); 312