1/*
2 * processor_driver.c - ACPI Processor Driver
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
9 * Copyright (C) 2013, Intel Corporation
10 * Rafael J. Wysocki <rafael.j.wysocki@intel.com>
11 *
12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
23 *
24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25 */
26
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/init.h>
30#include <linux/cpufreq.h>
31#include <linux/cpu.h>
32#include <linux/cpuidle.h>
33#include <linux/slab.h>
34#include <linux/acpi.h>
35
36#include <acpi/processor.h>
37
38#include "internal.h"
39
40#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
41#define ACPI_PROCESSOR_NOTIFY_POWER 0x81
42#define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82
43
44#define _COMPONENT ACPI_PROCESSOR_COMPONENT
45ACPI_MODULE_NAME("processor_driver");
46
47MODULE_AUTHOR("Paul Diefenbaugh");
48MODULE_DESCRIPTION("ACPI Processor Driver");
49MODULE_LICENSE("GPL");
50
51static int acpi_processor_start(struct device *dev);
52static int acpi_processor_stop(struct device *dev);
53
54static const struct acpi_device_id processor_device_ids[] = {
55 {ACPI_PROCESSOR_OBJECT_HID, 0},
56 {ACPI_PROCESSOR_DEVICE_HID, 0},
57 {"", 0},
58};
59MODULE_DEVICE_TABLE(acpi, processor_device_ids);
60
61static struct device_driver acpi_processor_driver = {
62 .name = "processor",
63 .bus = &cpu_subsys,
64 .acpi_match_table = processor_device_ids,
65 .probe = acpi_processor_start,
66 .remove = acpi_processor_stop,
67};
68
69static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
70{
71 struct acpi_device *device = data;
72 struct acpi_processor *pr;
73 int saved;
74
75 if (device->handle != handle)
76 return;
77
78 pr = acpi_driver_data(device);
79 if (!pr)
80 return;
81
82 switch (event) {
83 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
84 saved = pr->performance_platform_limit;
85 acpi_processor_ppc_has_changed(pr, 1);
86 if (saved == pr->performance_platform_limit)
87 break;
88 acpi_bus_generate_netlink_event(device->pnp.device_class,
89 dev_name(&device->dev), event,
90 pr->performance_platform_limit);
91 break;
92 case ACPI_PROCESSOR_NOTIFY_POWER:
93 acpi_processor_power_state_has_changed(pr);
94 acpi_bus_generate_netlink_event(device->pnp.device_class,
95 dev_name(&device->dev), event, 0);
96 break;
97 case ACPI_PROCESSOR_NOTIFY_THROTTLING:
98 acpi_processor_tstate_has_changed(pr);
99 acpi_bus_generate_netlink_event(device->pnp.device_class,
100 dev_name(&device->dev), event, 0);
101 break;
102 default:
103 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
104 "Unsupported event [0x%x]\n", event));
105 break;
106 }
107
108 return;
109}
110
111static int __acpi_processor_start(struct acpi_device *device);
112
113static int acpi_soft_cpu_online(unsigned int cpu)
114{
115 struct acpi_processor *pr = per_cpu(processors, cpu);
116 struct acpi_device *device;
117
118 if (!pr || acpi_bus_get_device(pr->handle, &device))
119 return 0;
120 /*
121 * CPU got physically hotplugged and onlined for the first time:
122 * Initialize missing things.
123 */
124 if (pr->flags.need_hotplug_init) {
125 int ret;
126
127 pr_info("Will online and init hotplugged CPU: %d\n",
128 pr->id);
129 pr->flags.need_hotplug_init = 0;
130 ret = __acpi_processor_start(device);
131 WARN(ret, "Failed to start CPU: %d\n", pr->id);
132 } else {
133 /* Normal CPU soft online event. */
134 acpi_processor_ppc_has_changed(pr, 0);
135 acpi_processor_hotplug(pr);
136 acpi_processor_reevaluate_tstate(pr, false);
137 acpi_processor_tstate_has_changed(pr);
138 }
139 return 0;
140}
141
142static int acpi_soft_cpu_dead(unsigned int cpu)
143{
144 struct acpi_processor *pr = per_cpu(processors, cpu);
145 struct acpi_device *device;
146
147 if (!pr || acpi_bus_get_device(pr->handle, &device))
148 return 0;
149
150 acpi_processor_reevaluate_tstate(pr, true);
151 return 0;
152}
153
154#ifdef CONFIG_ACPI_CPU_FREQ_PSS
155static int acpi_pss_perf_init(struct acpi_processor *pr,
156 struct acpi_device *device)
157{
158 int result = 0;
159
160 acpi_processor_ppc_has_changed(pr, 0);
161
162 acpi_processor_get_throttling_info(pr);
163
164 if (pr->flags.throttling)
165 pr->flags.limit = 1;
166
167 pr->cdev = thermal_cooling_device_register("Processor", device,
168 &processor_cooling_ops);
169 if (IS_ERR(pr->cdev)) {
170 result = PTR_ERR(pr->cdev);
171 return result;
172 }
173
174 dev_dbg(&device->dev, "registered as cooling_device%d\n",
175 pr->cdev->id);
176
177 result = sysfs_create_link(&device->dev.kobj,
178 &pr->cdev->device.kobj,
179 "thermal_cooling");
180 if (result) {
181 dev_err(&device->dev,
182 "Failed to create sysfs link 'thermal_cooling'\n");
183 goto err_thermal_unregister;
184 }
185
186 result = sysfs_create_link(&pr->cdev->device.kobj,
187 &device->dev.kobj,
188 "device");
189 if (result) {
190 dev_err(&pr->cdev->device,
191 "Failed to create sysfs link 'device'\n");
192 goto err_remove_sysfs_thermal;
193 }
194
195 return 0;
196
197 err_remove_sysfs_thermal:
198 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
199 err_thermal_unregister:
200 thermal_cooling_device_unregister(pr->cdev);
201
202 return result;
203}
204
205static void acpi_pss_perf_exit(struct acpi_processor *pr,
206 struct acpi_device *device)
207{
208 if (pr->cdev) {
209 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
210 sysfs_remove_link(&pr->cdev->device.kobj, "device");
211 thermal_cooling_device_unregister(pr->cdev);
212 pr->cdev = NULL;
213 }
214}
215#else
216static inline int acpi_pss_perf_init(struct acpi_processor *pr,
217 struct acpi_device *device)
218{
219 return 0;
220}
221
222static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
223 struct acpi_device *device) {}
224#endif /* CONFIG_ACPI_CPU_FREQ_PSS */
225
226static int __acpi_processor_start(struct acpi_device *device)
227{
228 struct acpi_processor *pr = acpi_driver_data(device);
229 acpi_status status;
230 int result = 0;
231
232 if (!pr)
233 return -ENODEV;
234
235 if (pr->flags.need_hotplug_init)
236 return 0;
237
238 result = acpi_cppc_processor_probe(pr);
239 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
240 dev_dbg(&device->dev, "CPPC data invalid or not present\n");
241
242 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
243 acpi_processor_power_init(pr);
244
245 result = acpi_pss_perf_init(pr, device);
246 if (result)
247 goto err_power_exit;
248
249 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
250 acpi_processor_notify, device);
251 if (ACPI_SUCCESS(status))
252 return 0;
253
254 result = -ENODEV;
255 acpi_pss_perf_exit(pr, device);
256
257err_power_exit:
258 acpi_processor_power_exit(pr);
259 return result;
260}
261
262static int acpi_processor_start(struct device *dev)
263{
264 struct acpi_device *device = ACPI_COMPANION(dev);
265 int ret;
266
267 if (!device)
268 return -ENODEV;
269
270 /* Protect against concurrent CPU hotplug operations */
271 cpu_hotplug_disable();
272 ret = __acpi_processor_start(device);
273 cpu_hotplug_enable();
274 return ret;
275}
276
277static int acpi_processor_stop(struct device *dev)
278{
279 struct acpi_device *device = ACPI_COMPANION(dev);
280 struct acpi_processor *pr;
281
282 if (!device)
283 return 0;
284
285 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
286 acpi_processor_notify);
287
288 pr = acpi_driver_data(device);
289 if (!pr)
290 return 0;
291 acpi_processor_power_exit(pr);
292
293 acpi_pss_perf_exit(pr, device);
294
295 acpi_cppc_processor_exit(pr);
296
297 return 0;
298}
299
300/*
301 * We keep the driver loaded even when ACPI is not running.
302 * This is needed for the powernow-k8 driver, that works even without
303 * ACPI, but needs symbols from this driver
304 */
305static enum cpuhp_state hp_online;
306static int __init acpi_processor_driver_init(void)
307{
308 int result = 0;
309
310 if (acpi_disabled)
311 return 0;
312
313 result = driver_register(&acpi_processor_driver);
314 if (result < 0)
315 return result;
316
317 result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
318 "acpi/cpu-drv:online",
319 acpi_soft_cpu_online, NULL);
320 if (result < 0)
321 goto err;
322 hp_online = result;
323 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
324 NULL, acpi_soft_cpu_dead);
325
326 acpi_thermal_cpufreq_init();
327 acpi_processor_ppc_init();
328 acpi_processor_throttling_init();
329 return 0;
330err:
331 driver_unregister(&acpi_processor_driver);
332 return result;
333}
334
335static void __exit acpi_processor_driver_exit(void)
336{
337 if (acpi_disabled)
338 return;
339
340 acpi_processor_ppc_exit();
341 acpi_thermal_cpufreq_exit();
342 cpuhp_remove_state_nocalls(hp_online);
343 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
344 driver_unregister(&acpi_processor_driver);
345}
346
347module_init(acpi_processor_driver_init);
348module_exit(acpi_processor_driver_exit);
349
350MODULE_ALIAS("processor");
351