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 
124 	/*
125 	 * CPU_STARTING and CPU_DYING must not sleep. Return here since
126 	 * acpi_bus_get_device() may sleep.
127 	 */
128 	if (action == CPU_STARTING || action == CPU_DYING)
129 		return NOTIFY_DONE;
130 
131 	if (!pr || acpi_bus_get_device(pr->handle, &device))
132 		return NOTIFY_DONE;
133 
134 	if (action == CPU_ONLINE) {
135 		/*
136 		 * CPU got physically hotplugged and onlined for the first time:
137 		 * Initialize missing things.
138 		 */
139 		if (pr->flags.need_hotplug_init) {
140 			int ret;
141 
142 			pr_info("Will online and init hotplugged CPU: %d\n",
143 				pr->id);
144 			pr->flags.need_hotplug_init = 0;
145 			ret = __acpi_processor_start(device);
146 			WARN(ret, "Failed to start CPU: %d\n", pr->id);
147 		} else {
148 			/* Normal CPU soft online event. */
149 			acpi_processor_ppc_has_changed(pr, 0);
150 			acpi_processor_hotplug(pr);
151 			acpi_processor_reevaluate_tstate(pr, action);
152 			acpi_processor_tstate_has_changed(pr);
153 		}
154 	} else if (action == CPU_DEAD) {
155 		/* Invalidate flag.throttling after the CPU is offline. */
156 		acpi_processor_reevaluate_tstate(pr, action);
157 	}
158 	return NOTIFY_OK;
159 }
160 
161 static struct notifier_block __refdata acpi_cpu_notifier = {
162 	    .notifier_call = acpi_cpu_soft_notify,
163 };
164 
165 static int __acpi_processor_start(struct acpi_device *device)
166 {
167 	struct acpi_processor *pr = acpi_driver_data(device);
168 	acpi_status status;
169 	int result = 0;
170 
171 	if (!pr)
172 		return -ENODEV;
173 
174 	if (pr->flags.need_hotplug_init)
175 		return 0;
176 
177 #ifdef CONFIG_CPU_FREQ
178 	acpi_processor_ppc_has_changed(pr, 0);
179 #endif
180 	acpi_processor_get_throttling_info(pr);
181 
182 	if (pr->flags.throttling)
183 		pr->flags.limit = 1;
184 
185 	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
186 		acpi_processor_power_init(pr);
187 
188 	pr->cdev = thermal_cooling_device_register("Processor", device,
189 						   &processor_cooling_ops);
190 	if (IS_ERR(pr->cdev)) {
191 		result = PTR_ERR(pr->cdev);
192 		goto err_power_exit;
193 	}
194 
195 	dev_dbg(&device->dev, "registered as cooling_device%d\n",
196 		pr->cdev->id);
197 
198 	result = sysfs_create_link(&device->dev.kobj,
199 				   &pr->cdev->device.kobj,
200 				   "thermal_cooling");
201 	if (result) {
202 		dev_err(&device->dev,
203 			"Failed to create sysfs link 'thermal_cooling'\n");
204 		goto err_thermal_unregister;
205 	}
206 	result = sysfs_create_link(&pr->cdev->device.kobj,
207 				   &device->dev.kobj,
208 				   "device");
209 	if (result) {
210 		dev_err(&pr->cdev->device,
211 			"Failed to create sysfs link 'device'\n");
212 		goto err_remove_sysfs_thermal;
213 	}
214 
215 	status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
216 					     acpi_processor_notify, device);
217 	if (ACPI_SUCCESS(status))
218 		return 0;
219 
220 	sysfs_remove_link(&pr->cdev->device.kobj, "device");
221  err_remove_sysfs_thermal:
222 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
223  err_thermal_unregister:
224 	thermal_cooling_device_unregister(pr->cdev);
225  err_power_exit:
226 	acpi_processor_power_exit(pr);
227 	return result;
228 }
229 
230 static int acpi_processor_start(struct device *dev)
231 {
232 	struct acpi_device *device = ACPI_COMPANION(dev);
233 
234 	if (!device)
235 		return -ENODEV;
236 
237 	return __acpi_processor_start(device);
238 }
239 
240 static int acpi_processor_stop(struct device *dev)
241 {
242 	struct acpi_device *device = ACPI_COMPANION(dev);
243 	struct acpi_processor *pr;
244 
245 	if (!device)
246 		return 0;
247 
248 	acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
249 				   acpi_processor_notify);
250 
251 	pr = acpi_driver_data(device);
252 	if (!pr)
253 		return 0;
254 
255 	acpi_processor_power_exit(pr);
256 
257 	if (pr->cdev) {
258 		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
259 		sysfs_remove_link(&pr->cdev->device.kobj, "device");
260 		thermal_cooling_device_unregister(pr->cdev);
261 		pr->cdev = NULL;
262 	}
263 	return 0;
264 }
265 
266 /*
267  * We keep the driver loaded even when ACPI is not running.
268  * This is needed for the powernow-k8 driver, that works even without
269  * ACPI, but needs symbols from this driver
270  */
271 
272 static int __init acpi_processor_driver_init(void)
273 {
274 	int result = 0;
275 
276 	if (acpi_disabled)
277 		return 0;
278 
279 	result = driver_register(&acpi_processor_driver);
280 	if (result < 0)
281 		return result;
282 
283 	acpi_processor_syscore_init();
284 	register_hotcpu_notifier(&acpi_cpu_notifier);
285 	acpi_thermal_cpufreq_init();
286 	acpi_processor_ppc_init();
287 	acpi_processor_throttling_init();
288 	return 0;
289 }
290 
291 static void __exit acpi_processor_driver_exit(void)
292 {
293 	if (acpi_disabled)
294 		return;
295 
296 	acpi_processor_ppc_exit();
297 	acpi_thermal_cpufreq_exit();
298 	unregister_hotcpu_notifier(&acpi_cpu_notifier);
299 	acpi_processor_syscore_exit();
300 	driver_unregister(&acpi_processor_driver);
301 }
302 
303 module_init(acpi_processor_driver_init);
304 module_exit(acpi_processor_driver_exit);
305 
306 MODULE_ALIAS("processor");
307