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)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
acpi_pss_perf_init(struct acpi_processor * pr)152 static inline void acpi_pss_perf_init(struct acpi_processor *pr) {}
153 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
154
__acpi_processor_start(struct acpi_device * device)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
acpi_processor_start(struct device * dev)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
acpi_processor_stop(struct device * dev)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
acpi_processor_notifier(struct notifier_block * nb,unsigned long event,void * data)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;
acpi_processor_driver_init(void)259 static int __init acpi_processor_driver_init(void)
260 {
261 int result = 0;
262
263 if (acpi_disabled)
264 return 0;
265
266 if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
267 CPUFREQ_POLICY_NOTIFIER)) {
268 acpi_processor_cpufreq_init = true;
269 acpi_processor_ignore_ppc_init();
270 }
271
272 result = driver_register(&acpi_processor_driver);
273 if (result < 0)
274 return result;
275
276 result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
277 "acpi/cpu-drv:online",
278 acpi_soft_cpu_online, NULL);
279 if (result < 0)
280 goto err;
281 hp_online = result;
282 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
283 NULL, acpi_soft_cpu_dead);
284
285 acpi_processor_throttling_init();
286 return 0;
287 err:
288 driver_unregister(&acpi_processor_driver);
289 return result;
290 }
291
acpi_processor_driver_exit(void)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