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
acpi_processor_notify(acpi_handle handle,u32 event,void * data)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
acpi_soft_cpu_online(unsigned int cpu)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
acpi_soft_cpu_dead(unsigned int cpu)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
acpi_pss_perf_init(struct acpi_processor * pr,struct acpi_device * device)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
acpi_pss_perf_exit(struct acpi_processor * pr,struct acpi_device * device)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
acpi_pss_perf_init(struct acpi_processor * pr,struct acpi_device * device)199 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
200 struct acpi_device *device)
201 {
202 return 0;
203 }
204
acpi_pss_perf_exit(struct acpi_processor * pr,struct acpi_device * device)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
__acpi_processor_start(struct acpi_device * device)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
acpi_processor_start(struct device * dev)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
acpi_processor_stop(struct device * dev)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
acpi_processor_notifier(struct notifier_block * nb,unsigned long event,void * data)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;
acpi_processor_driver_init(void)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
acpi_processor_driver_exit(void)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");
364