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)
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
acpi_soft_cpu_dead(unsigned int cpu)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
acpi_pss_perf_init(struct acpi_processor * pr,struct acpi_device * device)142 static int acpi_pss_perf_init(struct acpi_processor *pr,
143 struct acpi_device *device)
144 {
145 int result = 0;
146
147 acpi_processor_ppc_has_changed(pr, 0);
148
149 acpi_processor_get_throttling_info(pr);
150
151 if (pr->flags.throttling)
152 pr->flags.limit = 1;
153
154 pr->cdev = thermal_cooling_device_register("Processor", device,
155 &processor_cooling_ops);
156 if (IS_ERR(pr->cdev)) {
157 result = PTR_ERR(pr->cdev);
158 return result;
159 }
160
161 dev_dbg(&device->dev, "registered as cooling_device%d\n",
162 pr->cdev->id);
163
164 result = sysfs_create_link(&device->dev.kobj,
165 &pr->cdev->device.kobj,
166 "thermal_cooling");
167 if (result) {
168 dev_err(&device->dev,
169 "Failed to create sysfs link 'thermal_cooling'\n");
170 goto err_thermal_unregister;
171 }
172
173 result = sysfs_create_link(&pr->cdev->device.kobj,
174 &device->dev.kobj,
175 "device");
176 if (result) {
177 dev_err(&pr->cdev->device,
178 "Failed to create sysfs link 'device'\n");
179 goto err_remove_sysfs_thermal;
180 }
181
182 return 0;
183
184 err_remove_sysfs_thermal:
185 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
186 err_thermal_unregister:
187 thermal_cooling_device_unregister(pr->cdev);
188
189 return result;
190 }
191
acpi_pss_perf_exit(struct acpi_processor * pr,struct acpi_device * device)192 static void acpi_pss_perf_exit(struct acpi_processor *pr,
193 struct acpi_device *device)
194 {
195 if (pr->cdev) {
196 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
197 sysfs_remove_link(&pr->cdev->device.kobj, "device");
198 thermal_cooling_device_unregister(pr->cdev);
199 pr->cdev = NULL;
200 }
201 }
202 #else
acpi_pss_perf_init(struct acpi_processor * pr,struct acpi_device * device)203 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
204 struct acpi_device *device)
205 {
206 return 0;
207 }
208
acpi_pss_perf_exit(struct acpi_processor * pr,struct acpi_device * device)209 static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
210 struct acpi_device *device) {}
211 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
212
__acpi_processor_start(struct acpi_device * device)213 static int __acpi_processor_start(struct acpi_device *device)
214 {
215 struct acpi_processor *pr = acpi_driver_data(device);
216 acpi_status status;
217 int result = 0;
218
219 if (!pr)
220 return -ENODEV;
221
222 if (pr->flags.need_hotplug_init)
223 return 0;
224
225 result = acpi_cppc_processor_probe(pr);
226 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
227 dev_dbg(&device->dev, "CPPC data invalid or not present\n");
228
229 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
230 acpi_processor_power_init(pr);
231
232 result = acpi_pss_perf_init(pr, device);
233 if (result)
234 goto err_power_exit;
235
236 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
237 acpi_processor_notify, device);
238 if (ACPI_SUCCESS(status))
239 return 0;
240
241 result = -ENODEV;
242 acpi_pss_perf_exit(pr, device);
243
244 err_power_exit:
245 acpi_processor_power_exit(pr);
246 return result;
247 }
248
acpi_processor_start(struct device * dev)249 static int acpi_processor_start(struct device *dev)
250 {
251 struct acpi_device *device = ACPI_COMPANION(dev);
252 int ret;
253
254 if (!device)
255 return -ENODEV;
256
257 /* Protect against concurrent CPU hotplug operations */
258 cpu_hotplug_disable();
259 ret = __acpi_processor_start(device);
260 cpu_hotplug_enable();
261 return ret;
262 }
263
acpi_processor_stop(struct device * dev)264 static int acpi_processor_stop(struct device *dev)
265 {
266 struct acpi_device *device = ACPI_COMPANION(dev);
267 struct acpi_processor *pr;
268
269 if (!device)
270 return 0;
271
272 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
273 acpi_processor_notify);
274
275 pr = acpi_driver_data(device);
276 if (!pr)
277 return 0;
278 acpi_processor_power_exit(pr);
279
280 acpi_pss_perf_exit(pr, device);
281
282 acpi_cppc_processor_exit(pr);
283
284 return 0;
285 }
286
287 bool acpi_processor_cpufreq_init;
288
acpi_processor_notifier(struct notifier_block * nb,unsigned long event,void * data)289 static int acpi_processor_notifier(struct notifier_block *nb,
290 unsigned long event, void *data)
291 {
292 struct cpufreq_policy *policy = data;
293
294 if (event == CPUFREQ_CREATE_POLICY) {
295 acpi_thermal_cpufreq_init(policy);
296 acpi_processor_ppc_init(policy);
297 } else if (event == CPUFREQ_REMOVE_POLICY) {
298 acpi_processor_ppc_exit(policy);
299 acpi_thermal_cpufreq_exit(policy);
300 }
301
302 return 0;
303 }
304
305 static struct notifier_block acpi_processor_notifier_block = {
306 .notifier_call = acpi_processor_notifier,
307 };
308
309 /*
310 * We keep the driver loaded even when ACPI is not running.
311 * This is needed for the powernow-k8 driver, that works even without
312 * ACPI, but needs symbols from this driver
313 */
314 static enum cpuhp_state hp_online;
acpi_processor_driver_init(void)315 static int __init acpi_processor_driver_init(void)
316 {
317 int result = 0;
318
319 if (acpi_disabled)
320 return 0;
321
322 result = driver_register(&acpi_processor_driver);
323 if (result < 0)
324 return result;
325
326 result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
327 "acpi/cpu-drv:online",
328 acpi_soft_cpu_online, NULL);
329 if (result < 0)
330 goto err;
331 hp_online = result;
332 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
333 NULL, acpi_soft_cpu_dead);
334
335 if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
336 CPUFREQ_POLICY_NOTIFIER)) {
337 acpi_processor_cpufreq_init = true;
338 acpi_processor_ignore_ppc_init();
339 }
340
341 acpi_processor_throttling_init();
342 return 0;
343 err:
344 driver_unregister(&acpi_processor_driver);
345 return result;
346 }
347
acpi_processor_driver_exit(void)348 static void __exit acpi_processor_driver_exit(void)
349 {
350 if (acpi_disabled)
351 return;
352
353 if (acpi_processor_cpufreq_init) {
354 cpufreq_unregister_notifier(&acpi_processor_notifier_block,
355 CPUFREQ_POLICY_NOTIFIER);
356 acpi_processor_cpufreq_init = false;
357 }
358
359 cpuhp_remove_state_nocalls(hp_online);
360 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
361 driver_unregister(&acpi_processor_driver);
362 }
363
364 module_init(acpi_processor_driver_init);
365 module_exit(acpi_processor_driver_exit);
366
367 MODULE_ALIAS("processor");
368