summaryrefslogtreecommitdiff
path: root/drivers/platform/x86/intel-uncore-frequency.c
blob: 2b1a0734c3f87a2c482c8f113fa746796d2693f6 (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
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
// SPDX-License-Identifier: GPL-2.0
/*
 * Intel Uncore Frequency Setting
 * Copyright (c) 2019, Intel Corporation.
 * All rights reserved.
 *
 * Provide interface to set MSR 620 at a granularity of per die. On CPU online,
 * one control CPU is identified per die to read/write limit. This control CPU
 * is changed, if the CPU state is changed to offline. When the last CPU is
 * offline in a die then remove the sysfs object for that die.
 * The majority of actual code is related to sysfs create and read/write
 * attributes.
 *
 * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
 */

#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>

#define MSR_UNCORE_RATIO_LIMIT			0x620
#define UNCORE_FREQ_KHZ_MULTIPLIER		100000

/**
 * struct uncore_data -	Encapsulate all uncore data
 * @stored_uncore_data:	Last user changed MSR 620 value, which will be restored
 *			on system resume.
 * @initial_min_freq_khz: Sampled minimum uncore frequency at driver init
 * @initial_max_freq_khz: Sampled maximum uncore frequency at driver init
 * @control_cpu:	Designated CPU for a die to read/write
 * @valid:		Mark the data valid/invalid
 *
 * This structure is used to encapsulate all data related to uncore sysfs
 * settings for a die/package.
 */
struct uncore_data {
	struct kobject kobj;
	u64 stored_uncore_data;
	u32 initial_min_freq_khz;
	u32 initial_max_freq_khz;
	int control_cpu;
	bool valid;
};

#define to_uncore_data(a) container_of(a, struct uncore_data, kobj)

/* Max instances for uncore data, one for each die */
static int uncore_max_entries __read_mostly;
/* Storage for uncore data for all instances */
static struct uncore_data *uncore_instances;
/* Root of the all uncore sysfs kobjs */
struct kobject uncore_root_kobj;
/* Stores the CPU mask of the target CPUs to use during uncore read/write */
static cpumask_t uncore_cpu_mask;
/* CPU online callback register instance */
static enum cpuhp_state uncore_hp_state __read_mostly;
/* Mutex to control all mutual exclusions */
static DEFINE_MUTEX(uncore_lock);

struct uncore_attr {
	struct attribute attr;
	ssize_t (*show)(struct kobject *kobj,
			struct attribute *attr, char *buf);
	ssize_t (*store)(struct kobject *kobj,
			 struct attribute *attr, const char *c, ssize_t count);
};

#define define_one_uncore_ro(_name) \
static struct uncore_attr _name = \
__ATTR(_name, 0444, show_##_name, NULL)

#define define_one_uncore_rw(_name) \
static struct uncore_attr _name = \
__ATTR(_name, 0644, show_##_name, store_##_name)

#define show_uncore_data(member_name)					\
	static ssize_t show_##member_name(struct kobject *kobj,         \
					  struct attribute *attr,	\
					  char *buf)			\
	{                                                               \
		struct uncore_data *data = to_uncore_data(kobj);	\
		return scnprintf(buf, PAGE_SIZE, "%u\n",		\
				 data->member_name);			\
	}								\
	define_one_uncore_ro(member_name)

show_uncore_data(initial_min_freq_khz);
show_uncore_data(initial_max_freq_khz);

/* Common function to read MSR 0x620 and read min/max */
static int uncore_read_ratio(struct uncore_data *data, unsigned int *min,
			     unsigned int *max)
{
	u64 cap;
	int ret;

	ret = rdmsrl_on_cpu(data->control_cpu, MSR_UNCORE_RATIO_LIMIT, &cap);
	if (ret)
		return ret;

	*max = (cap & 0x7F) * UNCORE_FREQ_KHZ_MULTIPLIER;
	*min = ((cap & GENMASK(14, 8)) >> 8) * UNCORE_FREQ_KHZ_MULTIPLIER;

	return 0;
}

/* Common function to set min/max ratios to be used by sysfs callbacks */
static int uncore_write_ratio(struct uncore_data *data, unsigned int input,
			      int set_max)
{
	int ret;
	u64 cap;

	mutex_lock(&uncore_lock);

	input /= UNCORE_FREQ_KHZ_MULTIPLIER;
	if (!input || input > 0x7F) {
		ret = -EINVAL;
		goto finish_write;
	}

	ret = rdmsrl_on_cpu(data->control_cpu, MSR_UNCORE_RATIO_LIMIT, &cap);
	if (ret)
		goto finish_write;

	if (set_max) {
		cap &= ~0x7F;
		cap |= input;
	} else  {
		cap &= ~GENMASK(14, 8);
		cap |= (input << 8);
	}

	ret = wrmsrl_on_cpu(data->control_cpu, MSR_UNCORE_RATIO_LIMIT, cap);
	if (ret)
		goto finish_write;

	data->stored_uncore_data = cap;

finish_write:
	mutex_unlock(&uncore_lock);

	return ret;
}

static ssize_t store_min_max_freq_khz(struct kobject *kobj,
				      struct attribute *attr,
				      const char *buf, ssize_t count,
				      int min_max)
{
	struct uncore_data *data = to_uncore_data(kobj);
	unsigned int input;

	if (kstrtouint(buf, 10, &input))
		return -EINVAL;

	uncore_write_ratio(data, input, min_max);

	return count;
}

static ssize_t show_min_max_freq_khz(struct kobject *kobj,
				     struct attribute *attr,
				     char *buf, int min_max)
{
	struct uncore_data *data = to_uncore_data(kobj);
	unsigned int min, max;
	int ret;

	mutex_lock(&uncore_lock);
	ret = uncore_read_ratio(data, &min, &max);
	mutex_unlock(&uncore_lock);
	if (ret)
		return ret;

	if (min_max)
		return sprintf(buf, "%u\n", max);

	return sprintf(buf, "%u\n", min);
}

#define store_uncore_min_max(name, min_max)				\
	static ssize_t store_##name(struct kobject *kobj,		\
				    struct attribute *attr,		\
				    const char *buf, ssize_t count)	\
	{                                                               \
									\
		return store_min_max_freq_khz(kobj, attr, buf, count,	\
					      min_max);			\
	}

#define show_uncore_min_max(name, min_max)				\
	static ssize_t show_##name(struct kobject *kobj,		\
				   struct attribute *attr, char *buf)	\
	{                                                               \
									\
		return show_min_max_freq_khz(kobj, attr, buf, min_max); \
	}

store_uncore_min_max(min_freq_khz, 0);
store_uncore_min_max(max_freq_khz, 1);

show_uncore_min_max(min_freq_khz, 0);
show_uncore_min_max(max_freq_khz, 1);

define_one_uncore_rw(min_freq_khz);
define_one_uncore_rw(max_freq_khz);

static struct attribute *uncore_attrs[] = {
	&initial_min_freq_khz.attr,
	&initial_max_freq_khz.attr,
	&max_freq_khz.attr,
	&min_freq_khz.attr,
	NULL
};

static struct kobj_type uncore_ktype = {
	.sysfs_ops = &kobj_sysfs_ops,
	.default_attrs = uncore_attrs,
};

static struct kobj_type uncore_root_ktype = {
	.sysfs_ops = &kobj_sysfs_ops,
};

/* Caller provides protection */
static struct uncore_data *uncore_get_instance(unsigned int cpu)
{
	int id = topology_logical_die_id(cpu);

	if (id >= 0 && id < uncore_max_entries)
		return &uncore_instances[id];

	return NULL;
}

static void uncore_add_die_entry(int cpu)
{
	struct uncore_data *data;

	mutex_lock(&uncore_lock);
	data = uncore_get_instance(cpu);
	if (!data) {
		mutex_unlock(&uncore_lock);
		return;
	}

	if (data->valid) {
		/* control cpu changed */
		data->control_cpu = cpu;
	} else {
		char str[64];
		int ret;

		memset(data, 0, sizeof(*data));
		sprintf(str, "package_%02d_die_%02d",
			topology_physical_package_id(cpu),
			topology_die_id(cpu));

		uncore_read_ratio(data, &data->initial_min_freq_khz,
				  &data->initial_max_freq_khz);

		ret = kobject_init_and_add(&data->kobj, &uncore_ktype,
					   &uncore_root_kobj, str);
		if (!ret) {
			data->control_cpu = cpu;
			data->valid = true;
		}
	}
	mutex_unlock(&uncore_lock);
}

/* Last CPU in this die is offline, so remove sysfs entries */
static void uncore_remove_die_entry(int cpu)
{
	struct uncore_data *data;

	mutex_lock(&uncore_lock);
	data = uncore_get_instance(cpu);
	if (data) {
		kobject_put(&data->kobj);
		data->control_cpu = -1;
		data->valid = false;
	}
	mutex_unlock(&uncore_lock);
}

static int uncore_event_cpu_online(unsigned int cpu)
{
	int target;

	/* Check if there is an online cpu in the package for uncore MSR */
	target = cpumask_any_and(&uncore_cpu_mask, topology_die_cpumask(cpu));
	if (target < nr_cpu_ids)
		return 0;

	/* Use this CPU on this die as a control CPU */
	cpumask_set_cpu(cpu, &uncore_cpu_mask);
	uncore_add_die_entry(cpu);

	return 0;
}

static int uncore_event_cpu_offline(unsigned int cpu)
{
	int target;

	/* Check if existing cpu is used for uncore MSRs */
	if (!cpumask_test_and_clear_cpu(cpu, &uncore_cpu_mask))
		return 0;

	/* Find a new cpu to set uncore MSR */
	target = cpumask_any_but(topology_die_cpumask(cpu), cpu);

	if (target < nr_cpu_ids) {
		cpumask_set_cpu(target, &uncore_cpu_mask);
		uncore_add_die_entry(target);
	} else {
		uncore_remove_die_entry(cpu);
	}

	return 0;
}

static int uncore_pm_notify(struct notifier_block *nb, unsigned long mode,
			    void *_unused)
{
	int cpu;

	switch (mode) {
	case PM_POST_HIBERNATION:
	case PM_POST_RESTORE:
	case PM_POST_SUSPEND:
		for_each_cpu(cpu, &uncore_cpu_mask) {
			struct uncore_data *data;
			int ret;

			data = uncore_get_instance(cpu);
			if (!data || !data->valid || !data->stored_uncore_data)
				continue;

			ret = wrmsrl_on_cpu(cpu, MSR_UNCORE_RATIO_LIMIT,
					    data->stored_uncore_data);
			if (ret)
				return ret;
		}
		break;
	default:
		break;
	}
	return 0;
}

static struct notifier_block uncore_pm_nb = {
	.notifier_call = uncore_pm_notify,
};

#define ICPU(model)     { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }

static const struct x86_cpu_id intel_uncore_cpu_ids[] = {
	ICPU(INTEL_FAM6_BROADWELL_G),
	ICPU(INTEL_FAM6_BROADWELL_X),
	ICPU(INTEL_FAM6_BROADWELL_D),
	ICPU(INTEL_FAM6_SKYLAKE_X),
	ICPU(INTEL_FAM6_ICELAKE_X),
	ICPU(INTEL_FAM6_ICELAKE_D),
	{}
};

static int __init intel_uncore_init(void)
{
	const struct x86_cpu_id *id;
	int ret;

	id = x86_match_cpu(intel_uncore_cpu_ids);
	if (!id)
		return -ENODEV;

	uncore_max_entries = topology_max_packages() *
					topology_max_die_per_package();
	uncore_instances = kcalloc(uncore_max_entries,
				   sizeof(*uncore_instances), GFP_KERNEL);
	if (!uncore_instances)
		return -ENOMEM;

	ret = kobject_init_and_add(&uncore_root_kobj, &uncore_root_ktype,
				   &cpu_subsys.dev_root->kobj,
				   "intel_uncore_frequency");
	if (ret)
		goto err_free;

	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
				"platform/x86/uncore-freq:online",
				uncore_event_cpu_online,
				uncore_event_cpu_offline);
	if (ret < 0)
		goto err_rem_kobj;

	uncore_hp_state = ret;

	ret = register_pm_notifier(&uncore_pm_nb);
	if (ret)
		goto err_rem_state;

	return 0;

err_rem_state:
	cpuhp_remove_state(uncore_hp_state);
err_rem_kobj:
	kobject_put(&uncore_root_kobj);
err_free:
	kfree(uncore_instances);

	return ret;
}
module_init(intel_uncore_init)

static void __exit intel_uncore_exit(void)
{
	int i;

	unregister_pm_notifier(&uncore_pm_nb);
	cpuhp_remove_state(uncore_hp_state);
	for (i = 0; i < uncore_max_entries; ++i) {
		if (uncore_instances[i].valid)
			kobject_put(&uncore_instances[i].kobj);
	}
	kobject_put(&uncore_root_kobj);
	kfree(uncore_instances);
}
module_exit(intel_uncore_exit)

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Intel Uncore Frequency Limits Driver");