summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/processor_driver.c
blob: 4bd16b3f0781481f6cfd54d760f47f3ad54b405a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * processor_driver.c - ACPI Processor Driver
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
 *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
 *  			- Added processor hotplug support
 *  Copyright (C) 2013, Intel Corporation
 *                      Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
#include <linux/slab.h>
#include <linux/acpi.h>

#include <acpi/processor.h>

#include "internal.h"

#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
#define ACPI_PROCESSOR_NOTIFY_POWER	0x81
#define ACPI_PROCESSOR_NOTIFY_THROTTLING	0x82

MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION("ACPI Processor Driver");
MODULE_LICENSE("GPL");

static int acpi_processor_start(struct device *dev);
static int acpi_processor_stop(struct device *dev);

static const struct acpi_device_id processor_device_ids[] = {
	{ACPI_PROCESSOR_OBJECT_HID, 0},
	{ACPI_PROCESSOR_DEVICE_HID, 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, processor_device_ids);

static struct device_driver acpi_processor_driver = {
	.name = "processor",
	.bus = &cpu_subsys,
	.acpi_match_table = processor_device_ids,
	.probe = acpi_processor_start,
	.remove = acpi_processor_stop,
};

static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
{
	struct acpi_device *device = data;
	struct acpi_processor *pr;
	int saved;

	if (device->handle != handle)
		return;

	pr = acpi_driver_data(device);
	if (!pr)
		return;

	switch (event) {
	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
		saved = pr->performance_platform_limit;
		acpi_processor_ppc_has_changed(pr, 1);
		if (saved == pr->performance_platform_limit)
			break;
		acpi_bus_generate_netlink_event(device->pnp.device_class,
						  dev_name(&device->dev), event,
						  pr->performance_platform_limit);
		break;
	case ACPI_PROCESSOR_NOTIFY_POWER:
		acpi_processor_power_state_has_changed(pr);
		acpi_bus_generate_netlink_event(device->pnp.device_class,
						  dev_name(&device->dev), event, 0);
		break;
	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
		acpi_processor_tstate_has_changed(pr);
		acpi_bus_generate_netlink_event(device->pnp.device_class,
						  dev_name(&device->dev), event, 0);
		break;
	default:
		acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
		break;
	}

	return;
}

static int __acpi_processor_start(struct acpi_device *device);

static int acpi_soft_cpu_online(unsigned int cpu)
{
	struct acpi_processor *pr = per_cpu(processors, cpu);
	struct acpi_device *device;

	if (!pr)
		return 0;

	device = acpi_fetch_acpi_dev(pr->handle);
	if (!device)
		return 0;

	/*
	 * CPU got physically hotplugged and onlined for the first time:
	 * Initialize missing things.
	 */
	if (pr->flags.need_hotplug_init) {
		int ret;

		pr_info("Will online and init hotplugged CPU: %d\n",
			pr->id);
		pr->flags.need_hotplug_init = 0;
		ret = __acpi_processor_start(device);
		WARN(ret, "Failed to start CPU: %d\n", pr->id);
	} else {
		/* Normal CPU soft online event. */
		acpi_processor_ppc_has_changed(pr, 0);
		acpi_processor_hotplug(pr);
		acpi_processor_reevaluate_tstate(pr, false);
		acpi_processor_tstate_has_changed(pr);
	}
	return 0;
}

static int acpi_soft_cpu_dead(unsigned int cpu)
{
	struct acpi_processor *pr = per_cpu(processors, cpu);

	if (!pr || !acpi_fetch_acpi_dev(pr->handle))
		return 0;

	acpi_processor_reevaluate_tstate(pr, true);
	return 0;
}

#ifdef CONFIG_ACPI_CPU_FREQ_PSS
static void acpi_pss_perf_init(struct acpi_processor *pr)
{
	acpi_processor_ppc_has_changed(pr, 0);

	acpi_processor_get_throttling_info(pr);

	if (pr->flags.throttling)
		pr->flags.limit = 1;
}
#else
static inline void acpi_pss_perf_init(struct acpi_processor *pr) {}
#endif /* CONFIG_ACPI_CPU_FREQ_PSS */

static int __acpi_processor_start(struct acpi_device *device)
{
	struct acpi_processor *pr = acpi_driver_data(device);
	acpi_status status;
	int result = 0;

	if (!pr)
		return -ENODEV;

	if (pr->flags.need_hotplug_init)
		return 0;

	result = acpi_cppc_processor_probe(pr);
	if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
		dev_dbg(&device->dev, "CPPC data invalid or not present\n");

	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
		acpi_processor_power_init(pr);

	acpi_pss_perf_init(pr);

	result = acpi_processor_thermal_init(pr, device);
	if (result)
		goto err_power_exit;

	status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
					     acpi_processor_notify, device);
	if (ACPI_SUCCESS(status))
		return 0;

	result = -ENODEV;
	acpi_processor_thermal_exit(pr, device);

err_power_exit:
	acpi_processor_power_exit(pr);
	return result;
}

static int acpi_processor_start(struct device *dev)
{
	struct acpi_device *device = ACPI_COMPANION(dev);
	int ret;

	if (!device)
		return -ENODEV;

	/* Protect against concurrent CPU hotplug operations */
	cpu_hotplug_disable();
	ret = __acpi_processor_start(device);
	cpu_hotplug_enable();
	return ret;
}

static int acpi_processor_stop(struct device *dev)
{
	struct acpi_device *device = ACPI_COMPANION(dev);
	struct acpi_processor *pr;

	if (!device)
		return 0;

	acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
				   acpi_processor_notify);

	pr = acpi_driver_data(device);
	if (!pr)
		return 0;
	acpi_processor_power_exit(pr);

	acpi_cppc_processor_exit(pr);

	acpi_processor_thermal_exit(pr, device);

	return 0;
}

bool acpi_processor_cpufreq_init;

static int acpi_processor_notifier(struct notifier_block *nb,
				   unsigned long event, void *data)
{
	struct cpufreq_policy *policy = data;

	if (event == CPUFREQ_CREATE_POLICY) {
		acpi_thermal_cpufreq_init(policy);
		acpi_processor_ppc_init(policy);
	} else if (event == CPUFREQ_REMOVE_POLICY) {
		acpi_processor_ppc_exit(policy);
		acpi_thermal_cpufreq_exit(policy);
	}

	return 0;
}

static struct notifier_block acpi_processor_notifier_block = {
	.notifier_call = acpi_processor_notifier,
};

/*
 * We keep the driver loaded even when ACPI is not running.
 * This is needed for the powernow-k8 driver, that works even without
 * ACPI, but needs symbols from this driver
 */
static enum cpuhp_state hp_online;
static int __init acpi_processor_driver_init(void)
{
	int result = 0;

	if (acpi_disabled)
		return 0;

	if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
				       CPUFREQ_POLICY_NOTIFIER)) {
		acpi_processor_cpufreq_init = true;
		acpi_processor_ignore_ppc_init();
	}

	result = driver_register(&acpi_processor_driver);
	if (result < 0)
		return result;

	result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
					   "acpi/cpu-drv:online",
					   acpi_soft_cpu_online, NULL);
	if (result < 0)
		goto err;
	hp_online = result;
	cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
				  NULL, acpi_soft_cpu_dead);

	acpi_processor_throttling_init();
	return 0;
err:
	driver_unregister(&acpi_processor_driver);
	return result;
}

static void __exit acpi_processor_driver_exit(void)
{
	if (acpi_disabled)
		return;

	if (acpi_processor_cpufreq_init) {
		cpufreq_unregister_notifier(&acpi_processor_notifier_block,
					    CPUFREQ_POLICY_NOTIFIER);
		acpi_processor_cpufreq_init = false;
	}

	cpuhp_remove_state_nocalls(hp_online);
	cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
	driver_unregister(&acpi_processor_driver);
}

module_init(acpi_processor_driver_init);
module_exit(acpi_processor_driver_exit);

MODULE_ALIAS("processor");