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
45 ACPI_MODULE_NAME("processor_driver");
46
47 MODULE_AUTHOR("Paul Diefenbaugh");
48 MODULE_DESCRIPTION("ACPI Processor Driver");
49 MODULE_LICENSE("GPL");
50
51 static int acpi_processor_start(struct device *dev);
52 static int acpi_processor_stop(struct device *dev);
53
54 static const struct acpi_device_id processor_device_ids[] = {
55 {ACPI_PROCESSOR_OBJECT_HID, 0},
56 {ACPI_PROCESSOR_DEVICE_HID, 0},
57 {"", 0},
58 };
59 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
60
61 static 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
acpi_processor_notify(acpi_handle handle,u32 event,void * data)69 static 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_cst_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
111 static int __acpi_processor_start(struct acpi_device *device);
112
acpi_cpu_soft_notify(struct notifier_block * nfb,unsigned long action,void * hcpu)113 static int acpi_cpu_soft_notify(struct notifier_block *nfb,
114 unsigned long action, void *hcpu)
115 {
116 unsigned int cpu = (unsigned long)hcpu;
117 struct acpi_processor *pr = per_cpu(processors, cpu);
118 struct acpi_device *device;
119 action &= ~CPU_TASKS_FROZEN;
120
121 /*
122 * CPU_STARTING and CPU_DYING must not sleep. Return here since
123 * acpi_bus_get_device() may sleep.
124 */
125 if (action == CPU_STARTING || action == CPU_DYING)
126 return NOTIFY_DONE;
127
128 if (!pr || acpi_bus_get_device(pr->handle, &device))
129 return NOTIFY_DONE;
130
131 if (action == CPU_ONLINE) {
132 /*
133 * CPU got physically hotplugged and onlined for the first time:
134 * Initialize missing things.
135 */
136 if (pr->flags.need_hotplug_init) {
137 int ret;
138
139 pr_info("Will online and init hotplugged CPU: %d\n",
140 pr->id);
141 pr->flags.need_hotplug_init = 0;
142 ret = __acpi_processor_start(device);
143 WARN(ret, "Failed to start CPU: %d\n", pr->id);
144 } else {
145 /* Normal CPU soft online event. */
146 acpi_processor_ppc_has_changed(pr, 0);
147 acpi_processor_hotplug(pr);
148 acpi_processor_reevaluate_tstate(pr, action);
149 acpi_processor_tstate_has_changed(pr);
150 }
151 } else if (action == CPU_DEAD) {
152 /* Invalidate flag.throttling after the CPU is offline. */
153 acpi_processor_reevaluate_tstate(pr, action);
154 }
155 return NOTIFY_OK;
156 }
157
158 static struct notifier_block acpi_cpu_notifier = {
159 .notifier_call = acpi_cpu_soft_notify,
160 };
161
162 #ifdef CONFIG_ACPI_CPU_FREQ_PSS
acpi_pss_perf_init(struct acpi_processor * pr,struct acpi_device * device)163 static int acpi_pss_perf_init(struct acpi_processor *pr,
164 struct acpi_device *device)
165 {
166 int result = 0;
167
168 acpi_processor_ppc_has_changed(pr, 0);
169
170 acpi_processor_get_throttling_info(pr);
171
172 if (pr->flags.throttling)
173 pr->flags.limit = 1;
174
175 pr->cdev = thermal_cooling_device_register("Processor", device,
176 &processor_cooling_ops);
177 if (IS_ERR(pr->cdev)) {
178 result = PTR_ERR(pr->cdev);
179 return result;
180 }
181
182 dev_dbg(&device->dev, "registered as cooling_device%d\n",
183 pr->cdev->id);
184
185 result = sysfs_create_link(&device->dev.kobj,
186 &pr->cdev->device.kobj,
187 "thermal_cooling");
188 if (result) {
189 dev_err(&device->dev,
190 "Failed to create sysfs link 'thermal_cooling'\n");
191 goto err_thermal_unregister;
192 }
193
194 result = sysfs_create_link(&pr->cdev->device.kobj,
195 &device->dev.kobj,
196 "device");
197 if (result) {
198 dev_err(&pr->cdev->device,
199 "Failed to create sysfs link 'device'\n");
200 goto err_remove_sysfs_thermal;
201 }
202
203 return 0;
204
205 err_remove_sysfs_thermal:
206 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
207 err_thermal_unregister:
208 thermal_cooling_device_unregister(pr->cdev);
209
210 return result;
211 }
212
acpi_pss_perf_exit(struct acpi_processor * pr,struct acpi_device * device)213 static void acpi_pss_perf_exit(struct acpi_processor *pr,
214 struct acpi_device *device)
215 {
216 if (pr->cdev) {
217 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
218 sysfs_remove_link(&pr->cdev->device.kobj, "device");
219 thermal_cooling_device_unregister(pr->cdev);
220 pr->cdev = NULL;
221 }
222 }
223 #else
acpi_pss_perf_init(struct acpi_processor * pr,struct acpi_device * device)224 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
225 struct acpi_device *device)
226 {
227 return 0;
228 }
229
acpi_pss_perf_exit(struct acpi_processor * pr,struct acpi_device * device)230 static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
231 struct acpi_device *device) {}
232 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
233
__acpi_processor_start(struct acpi_device * device)234 static int __acpi_processor_start(struct acpi_device *device)
235 {
236 struct acpi_processor *pr = acpi_driver_data(device);
237 acpi_status status;
238 int result = 0;
239
240 if (!pr)
241 return -ENODEV;
242
243 if (pr->flags.need_hotplug_init)
244 return 0;
245
246 result = acpi_cppc_processor_probe(pr);
247 if (result)
248 return -ENODEV;
249
250 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
251 acpi_processor_power_init(pr);
252
253 result = acpi_pss_perf_init(pr, device);
254 if (result)
255 goto err_power_exit;
256
257 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
258 acpi_processor_notify, device);
259 if (ACPI_SUCCESS(status))
260 return 0;
261
262 result = -ENODEV;
263 acpi_pss_perf_exit(pr, device);
264
265 err_power_exit:
266 acpi_processor_power_exit(pr);
267 return result;
268 }
269
acpi_processor_start(struct device * dev)270 static int acpi_processor_start(struct device *dev)
271 {
272 struct acpi_device *device = ACPI_COMPANION(dev);
273 int ret;
274
275 if (!device)
276 return -ENODEV;
277
278 /* Protect against concurrent CPU hotplug operations */
279 get_online_cpus();
280 ret = __acpi_processor_start(device);
281 put_online_cpus();
282 return ret;
283 }
284
acpi_processor_stop(struct device * dev)285 static int acpi_processor_stop(struct device *dev)
286 {
287 struct acpi_device *device = ACPI_COMPANION(dev);
288 struct acpi_processor *pr;
289
290 if (!device)
291 return 0;
292
293 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
294 acpi_processor_notify);
295
296 pr = acpi_driver_data(device);
297 if (!pr)
298 return 0;
299 acpi_processor_power_exit(pr);
300
301 acpi_pss_perf_exit(pr, device);
302
303 acpi_cppc_processor_exit(pr);
304
305 return 0;
306 }
307
308 /*
309 * We keep the driver loaded even when ACPI is not running.
310 * This is needed for the powernow-k8 driver, that works even without
311 * ACPI, but needs symbols from this driver
312 */
313
acpi_processor_driver_init(void)314 static int __init acpi_processor_driver_init(void)
315 {
316 int result = 0;
317
318 if (acpi_disabled)
319 return 0;
320
321 result = driver_register(&acpi_processor_driver);
322 if (result < 0)
323 return result;
324
325 acpi_processor_syscore_init();
326 register_hotcpu_notifier(&acpi_cpu_notifier);
327 acpi_thermal_cpufreq_init();
328 acpi_processor_ppc_init();
329 acpi_processor_throttling_init();
330 return 0;
331 }
332
acpi_processor_driver_exit(void)333 static void __exit acpi_processor_driver_exit(void)
334 {
335 if (acpi_disabled)
336 return;
337
338 acpi_processor_ppc_exit();
339 acpi_thermal_cpufreq_exit();
340 unregister_hotcpu_notifier(&acpi_cpu_notifier);
341 acpi_processor_syscore_exit();
342 driver_unregister(&acpi_processor_driver);
343 }
344
345 module_init(acpi_processor_driver_init);
346 module_exit(acpi_processor_driver_exit);
347
348 MODULE_ALIAS("processor");
349