summaryrefslogtreecommitdiffstats
path: root/drivers/base/cacheinfo.c
blob: df0c66cb7ad3719016436dd7eb16ab1d3234568d (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
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
/*
 * cacheinfo support - processor cache information via sysfs
 *
 * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
 * Author: Sudeep Holla <sudeep.holla@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/bitops.h>
#include <linux/cacheinfo.h>
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/sysfs.h>

/* pointer to per cpu cacheinfo */
static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
#define ci_cacheinfo(cpu)	(&per_cpu(ci_cpu_cacheinfo, cpu))
#define cache_leaves(cpu)	(ci_cacheinfo(cpu)->num_leaves)
#define per_cpu_cacheinfo(cpu)	(ci_cacheinfo(cpu)->info_list)

struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
{
	return ci_cacheinfo(cpu);
}

#ifdef CONFIG_OF
static int cache_setup_of_node(unsigned int cpu)
{
	struct device_node *np;
	struct cacheinfo *this_leaf;
	struct device *cpu_dev = get_cpu_device(cpu);
	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
	unsigned int index = 0;

	/* skip if of_node is already populated */
	if (this_cpu_ci->info_list->of_node)
		return 0;

	if (!cpu_dev) {
		pr_err("No cpu device for CPU %d\n", cpu);
		return -ENODEV;
	}
	np = cpu_dev->of_node;
	if (!np) {
		pr_err("Failed to find cpu%d device node\n", cpu);
		return -ENOENT;
	}

	while (index < cache_leaves(cpu)) {
		this_leaf = this_cpu_ci->info_list + index;
		if (this_leaf->level != 1)
			np = of_find_next_cache_node(np);
		else
			np = of_node_get(np);/* cpu node itself */
		if (!np)
			break;
		this_leaf->of_node = np;
		index++;
	}

	if (index != cache_leaves(cpu)) /* not all OF nodes populated */
		return -ENOENT;

	return 0;
}

static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
					   struct cacheinfo *sib_leaf)
{
	return sib_leaf->of_node == this_leaf->of_node;
}
#else
static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
					   struct cacheinfo *sib_leaf)
{
	/*
	 * For non-DT systems, assume unique level 1 cache, system-wide
	 * shared caches for all other levels. This will be used only if
	 * arch specific code has not populated shared_cpu_map
	 */
	return !(this_leaf->level == 1);
}
#endif

static int cache_shared_cpu_map_setup(unsigned int cpu)
{
	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
	struct cacheinfo *this_leaf, *sib_leaf;
	unsigned int index;
	int ret;

	ret = cache_setup_of_node(cpu);
	if (ret)
		return ret;

	for (index = 0; index < cache_leaves(cpu); index++) {
		unsigned int i;

		this_leaf = this_cpu_ci->info_list + index;
		/* skip if shared_cpu_map is already populated */
		if (!cpumask_empty(&this_leaf->shared_cpu_map))
			continue;

		cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
		for_each_online_cpu(i) {
			struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);

			if (i == cpu || !sib_cpu_ci->info_list)
				continue;/* skip if itself or no cacheinfo */
			sib_leaf = sib_cpu_ci->info_list + index;
			if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
				cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
				cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
			}
		}
	}

	return 0;
}

static void cache_shared_cpu_map_remove(unsigned int cpu)
{
	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
	struct cacheinfo *this_leaf, *sib_leaf;
	unsigned int sibling, index;

	for (index = 0; index < cache_leaves(cpu); index++) {
		this_leaf = this_cpu_ci->info_list + index;
		for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
			struct cpu_cacheinfo *sib_cpu_ci;

			if (sibling == cpu) /* skip itself */
				continue;
			sib_cpu_ci = get_cpu_cacheinfo(sibling);
			sib_leaf = sib_cpu_ci->info_list + index;
			cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
			cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
		}
		of_node_put(this_leaf->of_node);
	}
}

static void free_cache_attributes(unsigned int cpu)
{
	cache_shared_cpu_map_remove(cpu);

	kfree(per_cpu_cacheinfo(cpu));
	per_cpu_cacheinfo(cpu) = NULL;
}

int __weak init_cache_level(unsigned int cpu)
{
	return -ENOENT;
}

int __weak populate_cache_leaves(unsigned int cpu)
{
	return -ENOENT;
}

static int detect_cache_attributes(unsigned int cpu)
{
	int ret;

	if (init_cache_level(cpu) || !cache_leaves(cpu))
		return -ENOENT;

	per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
					 sizeof(struct cacheinfo), GFP_KERNEL);
	if (per_cpu_cacheinfo(cpu) == NULL)
		return -ENOMEM;

	ret = populate_cache_leaves(cpu);
	if (ret)
		goto free_ci;
	/*
	 * For systems using DT for cache hierarcy, of_node and shared_cpu_map
	 * will be set up here only if they are not populated already
	 */
	ret = cache_shared_cpu_map_setup(cpu);
	if (ret) {
		pr_warn("Unable to detect cache hierarcy from DT for CPU %d\n",
			cpu);
		goto free_ci;
	}
	return 0;

free_ci:
	free_cache_attributes(cpu);
	return ret;
}

/* pointer to cpuX/cache device */
static DEFINE_PER_CPU(struct device *, ci_cache_dev);
#define per_cpu_cache_dev(cpu)	(per_cpu(ci_cache_dev, cpu))

static cpumask_t cache_dev_map;

/* pointer to array of devices for cpuX/cache/indexY */
static DEFINE_PER_CPU(struct device **, ci_index_dev);
#define per_cpu_index_dev(cpu)	(per_cpu(ci_index_dev, cpu))
#define per_cache_index_dev(cpu, idx)	((per_cpu_index_dev(cpu))[idx])

#define show_one(file_name, object)				\
static ssize_t file_name##_show(struct device *dev,		\
		struct device_attribute *attr, char *buf)	\
{								\
	struct cacheinfo *this_leaf = dev_get_drvdata(dev);	\
	return sprintf(buf, "%u\n", this_leaf->object);		\
}

show_one(level, level);
show_one(coherency_line_size, coherency_line_size);
show_one(number_of_sets, number_of_sets);
show_one(physical_line_partition, physical_line_partition);
show_one(ways_of_associativity, ways_of_associativity);

static ssize_t size_show(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	struct cacheinfo *this_leaf = dev_get_drvdata(dev);

	return sprintf(buf, "%uK\n", this_leaf->size >> 10);
}

static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
{
	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
	const struct cpumask *mask = &this_leaf->shared_cpu_map;

	return cpumap_print_to_pagebuf(list, buf, mask);
}

static ssize_t shared_cpu_map_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	return shared_cpumap_show_func(dev, false, buf);
}

static ssize_t shared_cpu_list_show(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	return shared_cpumap_show_func(dev, true, buf);
}

static ssize_t type_show(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	struct cacheinfo *this_leaf = dev_get_drvdata(dev);

	switch (this_leaf->type) {
	case CACHE_TYPE_DATA:
		return sprintf(buf, "Data\n");
	case CACHE_TYPE_INST:
		return sprintf(buf, "Instruction\n");
	case CACHE_TYPE_UNIFIED:
		return sprintf(buf, "Unified\n");
	default:
		return -EINVAL;
	}
}

static ssize_t allocation_policy_show(struct device *dev,
				      struct device_attribute *attr, char *buf)
{
	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
	unsigned int ci_attr = this_leaf->attributes;
	int n = 0;

	if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
		n = sprintf(buf, "ReadWriteAllocate\n");
	else if (ci_attr & CACHE_READ_ALLOCATE)
		n = sprintf(buf, "ReadAllocate\n");
	else if (ci_attr & CACHE_WRITE_ALLOCATE)
		n = sprintf(buf, "WriteAllocate\n");
	return n;
}

static ssize_t write_policy_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
	unsigned int ci_attr = this_leaf->attributes;
	int n = 0;

	if (ci_attr & CACHE_WRITE_THROUGH)
		n = sprintf(buf, "WriteThrough\n");
	else if (ci_attr & CACHE_WRITE_BACK)
		n = sprintf(buf, "WriteBack\n");
	return n;
}

static DEVICE_ATTR_RO(level);
static DEVICE_ATTR_RO(type);
static DEVICE_ATTR_RO(coherency_line_size);
static DEVICE_ATTR_RO(ways_of_associativity);
static DEVICE_ATTR_RO(number_of_sets);
static DEVICE_ATTR_RO(size);
static DEVICE_ATTR_RO(allocation_policy);
static DEVICE_ATTR_RO(write_policy);
static DEVICE_ATTR_RO(shared_cpu_map);
static DEVICE_ATTR_RO(shared_cpu_list);
static DEVICE_ATTR_RO(physical_line_partition);

static struct attribute *cache_default_attrs[] = {
	&dev_attr_type.attr,
	&dev_attr_level.attr,
	&dev_attr_shared_cpu_map.attr,
	&dev_attr_shared_cpu_list.attr,
	&dev_attr_coherency_line_size.attr,
	&dev_attr_ways_of_associativity.attr,
	&dev_attr_number_of_sets.attr,
	&dev_attr_size.attr,
	&dev_attr_allocation_policy.attr,
	&dev_attr_write_policy.attr,
	&dev_attr_physical_line_partition.attr,
	NULL
};

static umode_t
cache_default_attrs_is_visible(struct kobject *kobj,
			       struct attribute *attr, int unused)
{
	struct device *dev = kobj_to_dev(kobj);
	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
	const struct cpumask *mask = &this_leaf->shared_cpu_map;
	umode_t mode = attr->mode;

	if ((attr == &dev_attr_type.attr) && this_leaf->type)
		return mode;
	if ((attr == &dev_attr_level.attr) && this_leaf->level)
		return mode;
	if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
		return mode;
	if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
		return mode;
	if ((attr == &dev_attr_coherency_line_size.attr) &&
	    this_leaf->coherency_line_size)
		return mode;
	if ((attr == &dev_attr_ways_of_associativity.attr) &&
	    this_leaf->size) /* allow 0 = full associativity */
		return mode;
	if ((attr == &dev_attr_number_of_sets.attr) &&
	    this_leaf->number_of_sets)
		return mode;
	if ((attr == &dev_attr_size.attr) && this_leaf->size)
		return mode;
	if ((attr == &dev_attr_write_policy.attr) &&
	    (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
		return mode;
	if ((attr == &dev_attr_allocation_policy.attr) &&
	    (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
		return mode;
	if ((attr == &dev_attr_physical_line_partition.attr) &&
	    this_leaf->physical_line_partition)
		return mode;

	return 0;
}

static const struct attribute_group cache_default_group = {
	.attrs = cache_default_attrs,
	.is_visible = cache_default_attrs_is_visible,
};

static const struct attribute_group *cache_default_groups[] = {
	&cache_default_group,
	NULL,
};

static const struct attribute_group *cache_private_groups[] = {
	&cache_default_group,
	NULL, /* Place holder for private group */
	NULL,
};

const struct attribute_group *
__weak cache_get_priv_group(struct cacheinfo *this_leaf)
{
	return NULL;
}

static const struct attribute_group **
cache_get_attribute_groups(struct cacheinfo *this_leaf)
{
	const struct attribute_group *priv_group =
			cache_get_priv_group(this_leaf);

	if (!priv_group)
		return cache_default_groups;

	if (!cache_private_groups[1])
		cache_private_groups[1] = priv_group;

	return cache_private_groups;
}

/* Add/Remove cache interface for CPU device */
static void cpu_cache_sysfs_exit(unsigned int cpu)
{
	int i;
	struct device *ci_dev;

	if (per_cpu_index_dev(cpu)) {
		for (i = 0; i < cache_leaves(cpu); i++) {
			ci_dev = per_cache_index_dev(cpu, i);
			if (!ci_dev)
				continue;
			device_unregister(ci_dev);
		}
		kfree(per_cpu_index_dev(cpu));
		per_cpu_index_dev(cpu) = NULL;
	}
	device_unregister(per_cpu_cache_dev(cpu));
	per_cpu_cache_dev(cpu) = NULL;
}

static int cpu_cache_sysfs_init(unsigned int cpu)
{
	struct device *dev = get_cpu_device(cpu);

	if (per_cpu_cacheinfo(cpu) == NULL)
		return -ENOENT;

	per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
	if (IS_ERR(per_cpu_cache_dev(cpu)))
		return PTR_ERR(per_cpu_cache_dev(cpu));

	/* Allocate all required memory */
	per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
					 sizeof(struct device *), GFP_KERNEL);
	if (unlikely(per_cpu_index_dev(cpu) == NULL))
		goto err_out;

	return 0;

err_out:
	cpu_cache_sysfs_exit(cpu);
	return -ENOMEM;
}

static int cache_add_dev(unsigned int cpu)
{
	unsigned int i;
	int rc;
	struct device *ci_dev, *parent;
	struct cacheinfo *this_leaf;
	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
	const struct attribute_group **cache_groups;

	rc = cpu_cache_sysfs_init(cpu);
	if (unlikely(rc < 0))
		return rc;

	parent = per_cpu_cache_dev(cpu);
	for (i = 0; i < cache_leaves(cpu); i++) {
		this_leaf = this_cpu_ci->info_list + i;
		if (this_leaf->disable_sysfs)
			continue;
		cache_groups = cache_get_attribute_groups(this_leaf);
		ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
					   "index%1u", i);
		if (IS_ERR(ci_dev)) {
			rc = PTR_ERR(ci_dev);
			goto err;
		}
		per_cache_index_dev(cpu, i) = ci_dev;
	}
	cpumask_set_cpu(cpu, &cache_dev_map);

	return 0;
err:
	cpu_cache_sysfs_exit(cpu);
	return rc;
}

static void cache_remove_dev(unsigned int cpu)
{
	if (!cpumask_test_cpu(cpu, &cache_dev_map))
		return;
	cpumask_clear_cpu(cpu, &cache_dev_map);

	cpu_cache_sysfs_exit(cpu);
}

static int cacheinfo_cpu_callback(struct notifier_block *nfb,
				  unsigned long action, void *hcpu)
{
	unsigned int cpu = (unsigned long)hcpu;
	int rc = 0;

	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_ONLINE:
		rc = detect_cache_attributes(cpu);
		if (!rc)
			rc = cache_add_dev(cpu);
		break;
	case CPU_DEAD:
		cache_remove_dev(cpu);
		if (per_cpu_cacheinfo(cpu))
			free_cache_attributes(cpu);
		break;
	}
	return notifier_from_errno(rc);
}

static int __init cacheinfo_sysfs_init(void)
{
	int cpu, rc = 0;

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu) {
		rc = detect_cache_attributes(cpu);
		if (rc)
			goto out;
		rc = cache_add_dev(cpu);
		if (rc) {
			free_cache_attributes(cpu);
			pr_err("error populating cacheinfo..cpu%d\n", cpu);
			goto out;
		}
	}
	__hotcpu_notifier(cacheinfo_cpu_callback, 0);

out:
	cpu_notifier_register_done();
	return rc;
}

device_initcall(cacheinfo_sysfs_init);
OpenPOWER on IntegriCloud