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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  *  You should have received a copy of the GNU General Public License along
 25  *  with this program; if not, write to the Free Software Foundation, Inc.,
 26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 27  *
 28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 29  */
 30 
 31 #include <linux/kernel.h>
 32 #include <linux/module.h>
 33 #include <linux/init.h>
 34 #include <linux/cpufreq.h>
 35 #include <linux/cpu.h>
 36 #include <linux/cpuidle.h>
 37 #include <linux/slab.h>
 38 #include <linux/acpi.h>
 39 
 40 #include <acpi/processor.h>
 41 
 42 #include "internal.h"
 43 
 44 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
 45 #define ACPI_PROCESSOR_NOTIFY_POWER     0x81
 46 #define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
 47 
 48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
 49 ACPI_MODULE_NAME("processor_driver");
 50 
 51 MODULE_AUTHOR("Paul Diefenbaugh");
 52 MODULE_DESCRIPTION("ACPI Processor Driver");
 53 MODULE_LICENSE("GPL");
 54 
 55 static int acpi_processor_start(struct device *dev);
 56 static int acpi_processor_stop(struct device *dev);
 57 
 58 static const struct acpi_device_id processor_device_ids[] = {
 59         {ACPI_PROCESSOR_OBJECT_HID, 0},
 60         {ACPI_PROCESSOR_DEVICE_HID, 0},
 61         {"", 0},
 62 };
 63 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
 64 
 65 static struct device_driver acpi_processor_driver = {
 66         .name = "processor",
 67         .bus = &cpu_subsys,
 68         .acpi_match_table = processor_device_ids,
 69         .probe = acpi_processor_start,
 70         .remove = acpi_processor_stop,
 71 };
 72 
 73 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
 74 {
 75         struct acpi_device *device = data;
 76         struct acpi_processor *pr;
 77         int saved;
 78 
 79         if (device->handle != handle)
 80                 return;
 81 
 82         pr = acpi_driver_data(device);
 83         if (!pr)
 84                 return;
 85 
 86         switch (event) {
 87         case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
 88                 saved = pr->performance_platform_limit;
 89                 acpi_processor_ppc_has_changed(pr, 1);
 90                 if (saved == pr->performance_platform_limit)
 91                         break;
 92                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 93                                                   dev_name(&device->dev), event,
 94                                                   pr->performance_platform_limit);
 95                 break;
 96         case ACPI_PROCESSOR_NOTIFY_POWER:
 97                 acpi_processor_cst_has_changed(pr);
 98                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 99                                                   dev_name(&device->dev), event, 0);
100                 break;
101         case ACPI_PROCESSOR_NOTIFY_THROTTLING:
102                 acpi_processor_tstate_has_changed(pr);
103                 acpi_bus_generate_netlink_event(device->pnp.device_class,
104                                                   dev_name(&device->dev), event, 0);
105                 break;
106         default:
107                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
108                                   "Unsupported event [0x%x]\n", event));
109                 break;
110         }
111 
112         return;
113 }
114 
115 static int __acpi_processor_start(struct acpi_device *device);
116 
117 static int acpi_cpu_soft_notify(struct notifier_block *nfb,
118                                           unsigned long action, void *hcpu)
119 {
120         unsigned int cpu = (unsigned long)hcpu;
121         struct acpi_processor *pr = per_cpu(processors, cpu);
122         struct acpi_device *device;
123         action &= ~CPU_TASKS_FROZEN;
124 
125         /*
126          * CPU_STARTING and CPU_DYING must not sleep. Return here since
127          * acpi_bus_get_device() may sleep.
128          */
129         if (action == CPU_STARTING || action == CPU_DYING)
130                 return NOTIFY_DONE;
131 
132         if (!pr || acpi_bus_get_device(pr->handle, &device))
133                 return NOTIFY_DONE;
134 
135         if (action == CPU_ONLINE) {
136                 /*
137                  * CPU got physically hotplugged and onlined for the first time:
138                  * Initialize missing things.
139                  */
140                 if (pr->flags.need_hotplug_init) {
141                         int ret;
142 
143                         pr_info("Will online and init hotplugged CPU: %d\n",
144                                 pr->id);
145                         pr->flags.need_hotplug_init = 0;
146                         ret = __acpi_processor_start(device);
147                         WARN(ret, "Failed to start CPU: %d\n", pr->id);
148                 } else {
149                         /* Normal CPU soft online event. */
150                         acpi_processor_ppc_has_changed(pr, 0);
151                         acpi_processor_hotplug(pr);
152                         acpi_processor_reevaluate_tstate(pr, action);
153                         acpi_processor_tstate_has_changed(pr);
154                 }
155         } else if (action == CPU_DEAD) {
156                 /* Invalidate flag.throttling after the CPU is offline. */
157                 acpi_processor_reevaluate_tstate(pr, action);
158         }
159         return NOTIFY_OK;
160 }
161 
162 static struct notifier_block __refdata acpi_cpu_notifier = {
163             .notifier_call = acpi_cpu_soft_notify,
164 };
165 
166 static int __acpi_processor_start(struct acpi_device *device)
167 {
168         struct acpi_processor *pr = acpi_driver_data(device);
169         acpi_status status;
170         int result = 0;
171 
172         if (!pr)
173                 return -ENODEV;
174 
175         if (pr->flags.need_hotplug_init)
176                 return 0;
177 
178 #ifdef CONFIG_CPU_FREQ
179         acpi_processor_ppc_has_changed(pr, 0);
180 #endif
181         acpi_processor_get_throttling_info(pr);
182 
183         if (pr->flags.throttling)
184                 pr->flags.limit = 1;
185 
186         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
187                 acpi_processor_power_init(pr);
188 
189         pr->cdev = thermal_cooling_device_register("Processor", device,
190                                                    &processor_cooling_ops);
191         if (IS_ERR(pr->cdev)) {
192                 result = PTR_ERR(pr->cdev);
193                 goto err_power_exit;
194         }
195 
196         dev_dbg(&device->dev, "registered as cooling_device%d\n",
197                 pr->cdev->id);
198 
199         result = sysfs_create_link(&device->dev.kobj,
200                                    &pr->cdev->device.kobj,
201                                    "thermal_cooling");
202         if (result) {
203                 dev_err(&device->dev,
204                         "Failed to create sysfs link 'thermal_cooling'\n");
205                 goto err_thermal_unregister;
206         }
207         result = sysfs_create_link(&pr->cdev->device.kobj,
208                                    &device->dev.kobj,
209                                    "device");
210         if (result) {
211                 dev_err(&pr->cdev->device,
212                         "Failed to create sysfs link 'device'\n");
213                 goto err_remove_sysfs_thermal;
214         }
215 
216         status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
217                                              acpi_processor_notify, device);
218         if (ACPI_SUCCESS(status))
219                 return 0;
220 
221         sysfs_remove_link(&pr->cdev->device.kobj, "device");
222  err_remove_sysfs_thermal:
223         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
224  err_thermal_unregister:
225         thermal_cooling_device_unregister(pr->cdev);
226  err_power_exit:
227         acpi_processor_power_exit(pr);
228         return result;
229 }
230 
231 static int acpi_processor_start(struct device *dev)
232 {
233         struct acpi_device *device = ACPI_COMPANION(dev);
234 
235         if (!device)
236                 return -ENODEV;
237 
238         return __acpi_processor_start(device);
239 }
240 
241 static int acpi_processor_stop(struct device *dev)
242 {
243         struct acpi_device *device = ACPI_COMPANION(dev);
244         struct acpi_processor *pr;
245 
246         if (!device)
247                 return 0;
248 
249         acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
250                                    acpi_processor_notify);
251 
252         pr = acpi_driver_data(device);
253         if (!pr)
254                 return 0;
255 
256         acpi_processor_power_exit(pr);
257 
258         if (pr->cdev) {
259                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
260                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
261                 thermal_cooling_device_unregister(pr->cdev);
262                 pr->cdev = NULL;
263         }
264         return 0;
265 }
266 
267 /*
268  * We keep the driver loaded even when ACPI is not running.
269  * This is needed for the powernow-k8 driver, that works even without
270  * ACPI, but needs symbols from this driver
271  */
272 
273 static int __init acpi_processor_driver_init(void)
274 {
275         int result = 0;
276 
277         if (acpi_disabled)
278                 return 0;
279 
280         result = driver_register(&acpi_processor_driver);
281         if (result < 0)
282                 return result;
283 
284         acpi_processor_syscore_init();
285         register_hotcpu_notifier(&acpi_cpu_notifier);
286         acpi_thermal_cpufreq_init();
287         acpi_processor_ppc_init();
288         acpi_processor_throttling_init();
289         return 0;
290 }
291 
292 static void __exit acpi_processor_driver_exit(void)
293 {
294         if (acpi_disabled)
295                 return;
296 
297         acpi_processor_ppc_exit();
298         acpi_thermal_cpufreq_exit();
299         unregister_hotcpu_notifier(&acpi_cpu_notifier);
300         acpi_processor_syscore_exit();
301         driver_unregister(&acpi_processor_driver);
302 }
303 
304 module_init(acpi_processor_driver_init);
305 module_exit(acpi_processor_driver_exit);
306 
307 MODULE_ALIAS("processor");
308 

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