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
32MODULE_AUTHOR("Paul Diefenbaugh");
33MODULE_DESCRIPTION("ACPI Processor Driver");
34MODULE_LICENSE("GPL");
35
36static int acpi_processor_stop(struct device *dev);
37
38static const struct acpi_device_id processor_device_ids[] = {
39 {ACPI_PROCESSOR_OBJECT_HID, 0},
40 {ACPI_PROCESSOR_DEVICE_HID, .driver_data: 0},
41 {.id: "", .driver_data: 0},
42};
43MODULE_DEVICE_TABLE(acpi, processor_device_ids);
44
45static 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
52static 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;
57
58 if (device->handle != handle)
59 return;
60
61 pr = acpi_driver_data(d: 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, event_flag: 1);
69 if (saved == pr->performance_platform_limit)
70 break;
71 acpi_bus_generate_netlink_event(device->pnp.device_class,
72 dev_name(dev: &device->dev), event,
73 pr->performance_platform_limit);
74 break;
75 case ACPI_PROCESSOR_NOTIFY_POWER:
76 acpi_processor_power_state_has_changed(pr);
77 acpi_bus_generate_netlink_event(device->pnp.device_class,
78 dev_name(dev: &device->dev), event, 0);
79 break;
80 case ACPI_PROCESSOR_NOTIFY_THROTTLING:
81 acpi_processor_tstate_has_changed(pr);
82 acpi_bus_generate_netlink_event(device->pnp.device_class,
83 dev_name(dev: &device->dev), event, 0);
84 break;
85 case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED:
86 cpufreq_update_limits(cpu: pr->id);
87 acpi_bus_generate_netlink_event(device->pnp.device_class,
88 dev_name(dev: &device->dev), event, 0);
89 break;
90 default:
91 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
92 break;
93 }
94
95 return;
96}
97
98static int __acpi_processor_start(struct acpi_device *device);
99
100static int acpi_soft_cpu_online(unsigned int cpu)
101{
102 struct acpi_processor *pr = per_cpu(processors, cpu);
103 struct acpi_device *device;
104
105 if (!pr)
106 return 0;
107
108 device = acpi_fetch_acpi_dev(handle: pr->handle);
109 if (!device)
110 return 0;
111
112 /*
113 * CPU got physically hotplugged and onlined for the first time:
114 * Initialize missing things.
115 */
116 if (!pr->flags.previously_online) {
117 int ret;
118
119 ret = __acpi_processor_start(device);
120 WARN(ret, "Failed to start CPU: %d\n", pr->id);
121 } else {
122 /* Normal CPU soft online event. */
123 acpi_processor_ppc_has_changed(pr, event_flag: 0);
124 acpi_processor_hotplug(pr);
125 acpi_processor_reevaluate_tstate(pr, is_dead: false);
126 acpi_processor_tstate_has_changed(pr);
127 }
128 return 0;
129}
130
131static int acpi_soft_cpu_dead(unsigned int cpu)
132{
133 struct acpi_processor *pr = per_cpu(processors, cpu);
134
135 if (!pr || !acpi_fetch_acpi_dev(handle: pr->handle))
136 return 0;
137
138 acpi_processor_reevaluate_tstate(pr, is_dead: true);
139 return 0;
140}
141
142#ifdef CONFIG_ACPI_CPU_FREQ_PSS
143static void acpi_pss_perf_init(struct acpi_processor *pr)
144{
145 acpi_processor_ppc_has_changed(pr, event_flag: 0);
146
147 acpi_processor_get_throttling_info(pr);
148
149 if (pr->flags.throttling)
150 pr->flags.limit = 1;
151}
152#else
153static inline void acpi_pss_perf_init(struct acpi_processor *pr) {}
154#endif /* CONFIG_ACPI_CPU_FREQ_PSS */
155
156static int __acpi_processor_start(struct acpi_device *device)
157{
158 struct acpi_processor *pr = acpi_driver_data(d: device);
159 acpi_status status;
160 int result = 0;
161
162 if (!pr)
163 return -ENODEV;
164
165 result = acpi_cppc_processor_probe(pr);
166 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
167 dev_dbg(&device->dev, "CPPC data invalid or not present\n");
168
169 acpi_processor_power_init(pr);
170
171 acpi_pss_perf_init(pr);
172
173 result = acpi_processor_thermal_init(pr, device);
174 if (result)
175 goto err_power_exit;
176
177 status = acpi_install_notify_handler(device: device->handle, ACPI_DEVICE_NOTIFY,
178 handler: acpi_processor_notify, context: device);
179 if (!ACPI_SUCCESS(status)) {
180 result = -ENODEV;
181 goto err_thermal_exit;
182 }
183 pr->flags.previously_online = 1;
184
185 return 0;
186
187err_thermal_exit:
188 acpi_processor_thermal_exit(pr, device);
189err_power_exit:
190 acpi_processor_power_exit(pr);
191 return result;
192}
193
194static int acpi_processor_stop(struct device *dev)
195{
196 struct acpi_device *device = ACPI_COMPANION(dev);
197 struct acpi_processor *pr;
198
199 if (!device)
200 return 0;
201
202 acpi_remove_notify_handler(device: device->handle, ACPI_DEVICE_NOTIFY,
203 handler: acpi_processor_notify);
204
205 pr = acpi_driver_data(d: device);
206 if (!pr)
207 return 0;
208 acpi_processor_power_exit(pr);
209
210 acpi_cppc_processor_exit(pr);
211
212 acpi_processor_thermal_exit(pr, device);
213
214 return 0;
215}
216
217bool acpi_processor_cpufreq_init;
218
219static int acpi_processor_notifier(struct notifier_block *nb,
220 unsigned long event, void *data)
221{
222 struct cpufreq_policy *policy = data;
223
224 if (event == CPUFREQ_CREATE_POLICY) {
225 acpi_thermal_cpufreq_init(policy);
226 acpi_processor_ppc_init(policy);
227 } else if (event == CPUFREQ_REMOVE_POLICY) {
228 acpi_processor_ppc_exit(policy);
229 acpi_thermal_cpufreq_exit(policy);
230 }
231
232 return 0;
233}
234
235static struct notifier_block acpi_processor_notifier_block = {
236 .notifier_call = acpi_processor_notifier,
237};
238
239void __weak acpi_processor_init_invariance_cppc(void)
240{ }
241
242/*
243 * We keep the driver loaded even when ACPI is not running.
244 * This is needed for the powernow-k8 driver, that works even without
245 * ACPI, but needs symbols from this driver
246 */
247static enum cpuhp_state hp_online;
248static int __init acpi_processor_driver_init(void)
249{
250 int result = 0;
251
252 if (acpi_disabled)
253 return 0;
254
255 if (!cpufreq_register_notifier(nb: &acpi_processor_notifier_block,
256 CPUFREQ_POLICY_NOTIFIER)) {
257 acpi_processor_cpufreq_init = true;
258 acpi_processor_ignore_ppc_init();
259 }
260
261 result = driver_register(drv: &acpi_processor_driver);
262 if (result < 0)
263 return result;
264
265 acpi_processor_register_idle_driver();
266
267 result = cpuhp_setup_state(state: CPUHP_AP_ONLINE_DYN,
268 name: "acpi/cpu-drv:online",
269 startup: acpi_soft_cpu_online, NULL);
270 if (result < 0)
271 goto err;
272 hp_online = result;
273 cpuhp_setup_state_nocalls(state: CPUHP_ACPI_CPUDRV_DEAD, name: "acpi/cpu-drv:dead",
274 NULL, teardown: acpi_soft_cpu_dead);
275
276 acpi_processor_throttling_init();
277
278 /*
279 * Frequency invariance calculations on AMD platforms can't be run until
280 * after acpi_cppc_processor_probe() has been called for all online CPUs
281 */
282 acpi_processor_init_invariance_cppc();
283
284 acpi_idle_rescan_dead_smt_siblings();
285
286 return 0;
287err:
288 driver_unregister(drv: &acpi_processor_driver);
289 return result;
290}
291
292static 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(nb: &acpi_processor_notifier_block,
299 CPUFREQ_POLICY_NOTIFIER);
300 acpi_processor_cpufreq_init = false;
301 }
302
303 cpuhp_remove_state_nocalls(state: hp_online);
304 cpuhp_remove_state_nocalls(state: CPUHP_ACPI_CPUDRV_DEAD);
305 acpi_processor_unregister_idle_driver();
306 driver_unregister(drv: &acpi_processor_driver);
307}
308
309module_init(acpi_processor_driver_init);
310module_exit(acpi_processor_driver_exit);
311
312MODULE_ALIAS("processor");
313