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) 102 return 0; 103 104 device = acpi_fetch_acpi_dev(pr->handle); 105 if (!device) 106 return 0; 107 108 /* 109 * CPU got physically hotplugged and onlined for the first time: 110 * Initialize missing things. 111 */ 112 if (pr->flags.need_hotplug_init) { 113 int ret; 114 115 pr_info("Will online and init hotplugged CPU: %d\n", 116 pr->id); 117 pr->flags.need_hotplug_init = 0; 118 ret = __acpi_processor_start(device); 119 WARN(ret, "Failed to start CPU: %d\n", pr->id); 120 } else { 121 /* Normal CPU soft online event. */ 122 acpi_processor_ppc_has_changed(pr, 0); 123 acpi_processor_hotplug(pr); 124 acpi_processor_reevaluate_tstate(pr, false); 125 acpi_processor_tstate_has_changed(pr); 126 } 127 return 0; 128 } 129 130 static int acpi_soft_cpu_dead(unsigned int cpu) 131 { 132 struct acpi_processor *pr = per_cpu(processors, cpu); 133 134 if (!pr || !acpi_fetch_acpi_dev(pr->handle)) 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 void acpi_pss_perf_init(struct acpi_processor *pr) 143 { 144 acpi_processor_ppc_has_changed(pr, 0); 145 146 acpi_processor_get_throttling_info(pr); 147 148 if (pr->flags.throttling) 149 pr->flags.limit = 1; 150 } 151 #else 152 static inline void acpi_pss_perf_init(struct acpi_processor *pr) {} 153 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */ 154 155 static int __acpi_processor_start(struct acpi_device *device) 156 { 157 struct acpi_processor *pr = acpi_driver_data(device); 158 acpi_status status; 159 int result = 0; 160 161 if (!pr) 162 return -ENODEV; 163 164 if (pr->flags.need_hotplug_init) 165 return 0; 166 167 result = acpi_cppc_processor_probe(pr); 168 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS)) 169 dev_dbg(&device->dev, "CPPC data invalid or not present\n"); 170 171 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 172 acpi_processor_power_init(pr); 173 174 acpi_pss_perf_init(pr); 175 176 result = acpi_processor_thermal_init(pr, device); 177 if (result) 178 goto err_power_exit; 179 180 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 181 acpi_processor_notify, device); 182 if (ACPI_SUCCESS(status)) 183 return 0; 184 185 result = -ENODEV; 186 acpi_processor_thermal_exit(pr, device); 187 188 err_power_exit: 189 acpi_processor_power_exit(pr); 190 return result; 191 } 192 193 static int acpi_processor_start(struct device *dev) 194 { 195 struct acpi_device *device = ACPI_COMPANION(dev); 196 int ret; 197 198 if (!device) 199 return -ENODEV; 200 201 /* Protect against concurrent CPU hotplug operations */ 202 cpu_hotplug_disable(); 203 ret = __acpi_processor_start(device); 204 cpu_hotplug_enable(); 205 return ret; 206 } 207 208 static int acpi_processor_stop(struct device *dev) 209 { 210 struct acpi_device *device = ACPI_COMPANION(dev); 211 struct acpi_processor *pr; 212 213 if (!device) 214 return 0; 215 216 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, 217 acpi_processor_notify); 218 219 pr = acpi_driver_data(device); 220 if (!pr) 221 return 0; 222 acpi_processor_power_exit(pr); 223 224 acpi_cppc_processor_exit(pr); 225 226 acpi_processor_thermal_exit(pr, device); 227 228 return 0; 229 } 230 231 bool acpi_processor_cpufreq_init; 232 233 static int acpi_processor_notifier(struct notifier_block *nb, 234 unsigned long event, void *data) 235 { 236 struct cpufreq_policy *policy = data; 237 238 if (event == CPUFREQ_CREATE_POLICY) { 239 acpi_thermal_cpufreq_init(policy); 240 acpi_processor_ppc_init(policy); 241 } else if (event == CPUFREQ_REMOVE_POLICY) { 242 acpi_processor_ppc_exit(policy); 243 acpi_thermal_cpufreq_exit(policy); 244 } 245 246 return 0; 247 } 248 249 static struct notifier_block acpi_processor_notifier_block = { 250 .notifier_call = acpi_processor_notifier, 251 }; 252 253 /* 254 * We keep the driver loaded even when ACPI is not running. 255 * This is needed for the powernow-k8 driver, that works even without 256 * ACPI, but needs symbols from this driver 257 */ 258 static enum cpuhp_state hp_online; 259 static int __init acpi_processor_driver_init(void) 260 { 261 int result = 0; 262 263 if (acpi_disabled) 264 return 0; 265 266 result = driver_register(&acpi_processor_driver); 267 if (result < 0) 268 return result; 269 270 result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, 271 "acpi/cpu-drv:online", 272 acpi_soft_cpu_online, NULL); 273 if (result < 0) 274 goto err; 275 hp_online = result; 276 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead", 277 NULL, acpi_soft_cpu_dead); 278 279 if (!cpufreq_register_notifier(&acpi_processor_notifier_block, 280 CPUFREQ_POLICY_NOTIFIER)) { 281 acpi_processor_cpufreq_init = true; 282 acpi_processor_ignore_ppc_init(); 283 } 284 285 acpi_processor_throttling_init(); 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 driver_unregister(&acpi_processor_driver); 306 } 307 308 module_init(acpi_processor_driver_init); 309 module_exit(acpi_processor_driver_exit); 310 311 MODULE_ALIAS("processor"); 312