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Linux/drivers/acpi/processor_driver.c

  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 
 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_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 
111 static int __acpi_processor_start(struct acpi_device *device);
112 
113 static 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 
142 static 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
155 static 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 
205 static 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
216 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
217                 struct acpi_device *device)
218 {
219         return 0;
220 }
221 
222 static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
223                 struct acpi_device *device) {}
224 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */
225 
226 static 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_warn(&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 err_power_exit:
255         acpi_processor_power_exit(pr);
256         return result;
257 }
258 
259 static int acpi_processor_start(struct device *dev)
260 {
261         struct acpi_device *device = ACPI_COMPANION(dev);
262 
263         if (!device)
264                 return -ENODEV;
265 
266         return __acpi_processor_start(device);
267 }
268 
269 static int acpi_processor_stop(struct device *dev)
270 {
271         struct acpi_device *device = ACPI_COMPANION(dev);
272         struct acpi_processor *pr;
273 
274         if (!device)
275                 return 0;
276 
277         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
278                                    acpi_processor_notify);
279 
280         pr = acpi_driver_data(device);
281         if (!pr)
282                 return 0;
283         acpi_processor_power_exit(pr);
284 
285         acpi_pss_perf_exit(pr, device);
286 
287         acpi_cppc_processor_exit(pr);
288 
289         return 0;
290 }
291 
292 /*
293  * We keep the driver loaded even when ACPI is not running.
294  * This is needed for the powernow-k8 driver, that works even without
295  * ACPI, but needs symbols from this driver
296  */
297 static enum cpuhp_state hp_online;
298 static int __init acpi_processor_driver_init(void)
299 {
300         int result = 0;
301 
302         if (acpi_disabled)
303                 return 0;
304 
305         result = driver_register(&acpi_processor_driver);
306         if (result < 0)
307                 return result;
308 
309         result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
310                                            "acpi/cpu-drv:online",
311                                            acpi_soft_cpu_online, NULL);
312         if (result < 0)
313                 goto err;
314         hp_online = result;
315         cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
316                                   NULL, acpi_soft_cpu_dead);
317 
318         acpi_thermal_cpufreq_init();
319         acpi_processor_ppc_init();
320         acpi_processor_throttling_init();
321         return 0;
322 err:
323         driver_unregister(&acpi_processor_driver);
324         return result;
325 }
326 
327 static void __exit acpi_processor_driver_exit(void)
328 {
329         if (acpi_disabled)
330                 return;
331 
332         acpi_processor_ppc_exit();
333         acpi_thermal_cpufreq_exit();
334         cpuhp_remove_state_nocalls(hp_online);
335         cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
336         driver_unregister(&acpi_processor_driver);
337 }
338 
339 module_init(acpi_processor_driver_init);
340 module_exit(acpi_processor_driver_exit);
341 
342 MODULE_ALIAS("processor");
343 

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