summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/sysinfo.c
blob: f6f8f498c9be3959a433ffd7c1241ed6af663a2c (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
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright IBM Corp. 2001, 2009
 *  Author(s): Ulrich Weigand <Ulrich.Weigand@de.ibm.com>,
 *	       Martin Schwidefsky <schwidefsky@de.ibm.com>,
 */

#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <asm/asm-extable.h>
#include <asm/ebcdic.h>
#include <asm/debug.h>
#include <asm/sysinfo.h>
#include <asm/cpcmd.h>
#include <asm/topology.h>
#include <asm/fpu/api.h>

int topology_max_mnest;

static inline int __stsi(void *sysinfo, int fc, int sel1, int sel2, int *lvl)
{
	int r0 = (fc << 28) | sel1;
	int rc = 0;

	asm volatile(
		"	lr	0,%[r0]\n"
		"	lr	1,%[r1]\n"
		"	stsi	0(%[sysinfo])\n"
		"0:	jz	2f\n"
		"1:	lhi	%[rc],%[retval]\n"
		"2:	lr	%[r0],0\n"
		EX_TABLE(0b, 1b)
		: [r0] "+d" (r0), [rc] "+d" (rc)
		: [r1] "d" (sel2),
		  [sysinfo] "a" (sysinfo),
		  [retval] "K" (-EOPNOTSUPP)
		: "cc", "0", "1", "memory");
	*lvl = ((unsigned int) r0) >> 28;
	return rc;
}

/*
 * stsi - store system information
 *
 * Returns the current configuration level if function code 0 was specified.
 * Otherwise returns 0 on success or a negative value on error.
 */
int stsi(void *sysinfo, int fc, int sel1, int sel2)
{
	int lvl, rc;

	rc = __stsi(sysinfo, fc, sel1, sel2, &lvl);
	if (rc)
		return rc;
	return fc ? 0 : lvl;
}
EXPORT_SYMBOL(stsi);

#ifdef CONFIG_PROC_FS

static bool convert_ext_name(unsigned char encoding, char *name, size_t len)
{
	switch (encoding) {
	case 1: /* EBCDIC */
		EBCASC(name, len);
		break;
	case 2:	/* UTF-8 */
		break;
	default:
		return false;
	}
	return true;
}

static void stsi_1_1_1(struct seq_file *m, struct sysinfo_1_1_1 *info)
{
	bool has_var_cap;
	int i;

	if (stsi(info, 1, 1, 1))
		return;
	has_var_cap = !!info->model_var_cap[0];
	EBCASC(info->manufacturer, sizeof(info->manufacturer));
	EBCASC(info->type, sizeof(info->type));
	EBCASC(info->model, sizeof(info->model));
	EBCASC(info->sequence, sizeof(info->sequence));
	EBCASC(info->plant, sizeof(info->plant));
	EBCASC(info->model_capacity, sizeof(info->model_capacity));
	EBCASC(info->model_perm_cap, sizeof(info->model_perm_cap));
	EBCASC(info->model_temp_cap, sizeof(info->model_temp_cap));
	if (has_var_cap)
		EBCASC(info->model_var_cap, sizeof(info->model_var_cap));
	seq_printf(m, "Manufacturer:         %-16.16s\n", info->manufacturer);
	seq_printf(m, "Type:                 %-4.4s\n", info->type);
	if (info->lic)
		seq_printf(m, "LIC Identifier:       %016lx\n", info->lic);
	/*
	 * Sigh: the model field has been renamed with System z9
	 * to model_capacity and a new model field has been added
	 * after the plant field. To avoid confusing older programs
	 * the "Model:" prints "model_capacity model" or just
	 * "model_capacity" if the model string is empty .
	 */
	seq_printf(m, "Model:                %-16.16s", info->model_capacity);
	if (info->model[0] != '\0')
		seq_printf(m, " %-16.16s", info->model);
	seq_putc(m, '\n');
	seq_printf(m, "Sequence Code:        %-16.16s\n", info->sequence);
	seq_printf(m, "Plant:                %-4.4s\n", info->plant);
	seq_printf(m, "Model Capacity:       %-16.16s %08u\n",
		   info->model_capacity, info->model_cap_rating);
	if (info->model_perm_cap_rating)
		seq_printf(m, "Model Perm. Capacity: %-16.16s %08u\n",
			   info->model_perm_cap,
			   info->model_perm_cap_rating);
	if (info->model_temp_cap_rating)
		seq_printf(m, "Model Temp. Capacity: %-16.16s %08u\n",
			   info->model_temp_cap,
			   info->model_temp_cap_rating);
	if (has_var_cap && info->model_var_cap_rating)
		seq_printf(m, "Model Var. Capacity:  %-16.16s %08u\n",
			   info->model_var_cap,
			   info->model_var_cap_rating);
	if (info->ncr)
		seq_printf(m, "Nominal Cap. Rating:  %08u\n", info->ncr);
	if (info->npr)
		seq_printf(m, "Nominal Perm. Rating: %08u\n", info->npr);
	if (info->ntr)
		seq_printf(m, "Nominal Temp. Rating: %08u\n", info->ntr);
	if (has_var_cap && info->nvr)
		seq_printf(m, "Nominal Var. Rating:  %08u\n", info->nvr);
	if (info->cai) {
		seq_printf(m, "Capacity Adj. Ind.:   %d\n", info->cai);
		seq_printf(m, "Capacity Ch. Reason:  %d\n", info->ccr);
		seq_printf(m, "Capacity Transient:   %d\n", info->t);
	}
	if (info->p) {
		for (i = 1; i <= ARRAY_SIZE(info->typepct); i++) {
			seq_printf(m, "Type %d Percentage:    %d\n",
				   i, info->typepct[i - 1]);
		}
	}
}

static void stsi_15_1_x(struct seq_file *m, struct sysinfo_15_1_x *info)
{
	int i;

	seq_putc(m, '\n');
	if (!MACHINE_HAS_TOPOLOGY)
		return;
	if (stsi(info, 15, 1, topology_max_mnest))
		return;
	seq_printf(m, "CPU Topology HW:     ");
	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
		seq_printf(m, " %d", info->mag[i]);
	seq_putc(m, '\n');
#ifdef CONFIG_SCHED_TOPOLOGY
	store_topology(info);
	seq_printf(m, "CPU Topology SW:     ");
	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
		seq_printf(m, " %d", info->mag[i]);
	seq_putc(m, '\n');
#endif
}

static void stsi_1_2_2(struct seq_file *m, struct sysinfo_1_2_2 *info)
{
	struct sysinfo_1_2_2_extension *ext;
	int i;

	if (stsi(info, 1, 2, 2))
		return;
	ext = (struct sysinfo_1_2_2_extension *)
		((unsigned long) info + info->acc_offset);
	seq_printf(m, "CPUs Total:           %d\n", info->cpus_total);
	seq_printf(m, "CPUs Configured:      %d\n", info->cpus_configured);
	seq_printf(m, "CPUs Standby:         %d\n", info->cpus_standby);
	seq_printf(m, "CPUs Reserved:        %d\n", info->cpus_reserved);
	if (info->mt_installed) {
		seq_printf(m, "CPUs G-MTID:          %d\n", info->mt_gtid);
		seq_printf(m, "CPUs S-MTID:          %d\n", info->mt_stid);
	}
	/*
	 * Sigh 2. According to the specification the alternate
	 * capability field is a 32 bit floating point number
	 * if the higher order 8 bits are not zero. Printing
	 * a floating point number in the kernel is a no-no,
	 * always print the number as 32 bit unsigned integer.
	 * The user-space needs to know about the strange
	 * encoding of the alternate cpu capability.
	 */
	seq_printf(m, "Capability:           %u", info->capability);
	if (info->format == 1)
		seq_printf(m, " %u", ext->alt_capability);
	seq_putc(m, '\n');
	if (info->nominal_cap)
		seq_printf(m, "Nominal Capability:   %d\n", info->nominal_cap);
	if (info->secondary_cap)
		seq_printf(m, "Secondary Capability: %d\n", info->secondary_cap);
	for (i = 2; i <= info->cpus_total; i++) {
		seq_printf(m, "Adjustment %02d-way:    %u",
			   i, info->adjustment[i-2]);
		if (info->format == 1)
			seq_printf(m, " %u", ext->alt_adjustment[i-2]);
		seq_putc(m, '\n');
	}
}

static void stsi_2_2_2(struct seq_file *m, struct sysinfo_2_2_2 *info)
{
	if (stsi(info, 2, 2, 2))
		return;
	EBCASC(info->name, sizeof(info->name));
	seq_putc(m, '\n');
	seq_printf(m, "LPAR Number:          %d\n", info->lpar_number);
	seq_printf(m, "LPAR Characteristics: ");
	if (info->characteristics & LPAR_CHAR_DEDICATED)
		seq_printf(m, "Dedicated ");
	if (info->characteristics & LPAR_CHAR_SHARED)
		seq_printf(m, "Shared ");
	if (info->characteristics & LPAR_CHAR_LIMITED)
		seq_printf(m, "Limited ");
	seq_putc(m, '\n');
	seq_printf(m, "LPAR Name:            %-8.8s\n", info->name);
	seq_printf(m, "LPAR Adjustment:      %d\n", info->caf);
	seq_printf(m, "LPAR CPUs Total:      %d\n", info->cpus_total);
	seq_printf(m, "LPAR CPUs Configured: %d\n", info->cpus_configured);
	seq_printf(m, "LPAR CPUs Standby:    %d\n", info->cpus_standby);
	seq_printf(m, "LPAR CPUs Reserved:   %d\n", info->cpus_reserved);
	seq_printf(m, "LPAR CPUs Dedicated:  %d\n", info->cpus_dedicated);
	seq_printf(m, "LPAR CPUs Shared:     %d\n", info->cpus_shared);
	if (info->mt_installed) {
		seq_printf(m, "LPAR CPUs G-MTID:     %d\n", info->mt_gtid);
		seq_printf(m, "LPAR CPUs S-MTID:     %d\n", info->mt_stid);
		seq_printf(m, "LPAR CPUs PS-MTID:    %d\n", info->mt_psmtid);
	}
	if (convert_ext_name(info->vsne, info->ext_name, sizeof(info->ext_name))) {
		seq_printf(m, "LPAR Extended Name:   %-.256s\n", info->ext_name);
		seq_printf(m, "LPAR UUID:            %pUb\n", &info->uuid);
	}
}

static void print_ext_name(struct seq_file *m, int lvl,
			   struct sysinfo_3_2_2 *info)
{
	size_t len = sizeof(info->ext_names[lvl]);

	if (!convert_ext_name(info->vm[lvl].evmne, info->ext_names[lvl], len))
		return;
	seq_printf(m, "VM%02d Extended Name:   %-.256s\n", lvl,
		   info->ext_names[lvl]);
}

static void print_uuid(struct seq_file *m, int i, struct sysinfo_3_2_2 *info)
{
	if (uuid_is_null(&info->vm[i].uuid))
		return;
	seq_printf(m, "VM%02d UUID:            %pUb\n", i, &info->vm[i].uuid);
}

static void stsi_3_2_2(struct seq_file *m, struct sysinfo_3_2_2 *info)
{
	int i;

	if (stsi(info, 3, 2, 2))
		return;
	for (i = 0; i < info->count; i++) {
		EBCASC(info->vm[i].name, sizeof(info->vm[i].name));
		EBCASC(info->vm[i].cpi, sizeof(info->vm[i].cpi));
		seq_putc(m, '\n');
		seq_printf(m, "VM%02d Name:            %-8.8s\n", i, info->vm[i].name);
		seq_printf(m, "VM%02d Control Program: %-16.16s\n", i, info->vm[i].cpi);
		seq_printf(m, "VM%02d Adjustment:      %d\n", i, info->vm[i].caf);
		seq_printf(m, "VM%02d CPUs Total:      %d\n", i, info->vm[i].cpus_total);
		seq_printf(m, "VM%02d CPUs Configured: %d\n", i, info->vm[i].cpus_configured);
		seq_printf(m, "VM%02d CPUs Standby:    %d\n", i, info->vm[i].cpus_standby);
		seq_printf(m, "VM%02d CPUs Reserved:   %d\n", i, info->vm[i].cpus_reserved);
		print_ext_name(m, i, info);
		print_uuid(m, i, info);
	}
}

static int sysinfo_show(struct seq_file *m, void *v)
{
	void *info = (void *)get_zeroed_page(GFP_KERNEL);
	int level;

	if (!info)
		return 0;
	level = stsi(NULL, 0, 0, 0);
	if (level >= 1)
		stsi_1_1_1(m, info);
	if (level >= 1)
		stsi_15_1_x(m, info);
	if (level >= 1)
		stsi_1_2_2(m, info);
	if (level >= 2)
		stsi_2_2_2(m, info);
	if (level >= 3)
		stsi_3_2_2(m, info);
	free_page((unsigned long)info);
	return 0;
}

static int __init sysinfo_create_proc(void)
{
	proc_create_single("sysinfo", 0444, NULL, sysinfo_show);
	return 0;
}
device_initcall(sysinfo_create_proc);

#endif /* CONFIG_PROC_FS */

/*
 * Service levels interface.
 */

static DECLARE_RWSEM(service_level_sem);
static LIST_HEAD(service_level_list);

int register_service_level(struct service_level *slr)
{
	struct service_level *ptr;

	down_write(&service_level_sem);
	list_for_each_entry(ptr, &service_level_list, list)
		if (ptr == slr) {
			up_write(&service_level_sem);
			return -EEXIST;
		}
	list_add_tail(&slr->list, &service_level_list);
	up_write(&service_level_sem);
	return 0;
}
EXPORT_SYMBOL(register_service_level);

int unregister_service_level(struct service_level *slr)
{
	struct service_level *ptr, *next;
	int rc = -ENOENT;

	down_write(&service_level_sem);
	list_for_each_entry_safe(ptr, next, &service_level_list, list) {
		if (ptr != slr)
			continue;
		list_del(&ptr->list);
		rc = 0;
		break;
	}
	up_write(&service_level_sem);
	return rc;
}
EXPORT_SYMBOL(unregister_service_level);

static void *service_level_start(struct seq_file *m, loff_t *pos)
{
	down_read(&service_level_sem);
	return seq_list_start(&service_level_list, *pos);
}

static void *service_level_next(struct seq_file *m, void *p, loff_t *pos)
{
	return seq_list_next(p, &service_level_list, pos);
}

static void service_level_stop(struct seq_file *m, void *p)
{
	up_read(&service_level_sem);
}

static int service_level_show(struct seq_file *m, void *p)
{
	struct service_level *slr;

	slr = list_entry(p, struct service_level, list);
	slr->seq_print(m, slr);
	return 0;
}

static const struct seq_operations service_level_seq_ops = {
	.start		= service_level_start,
	.next		= service_level_next,
	.stop		= service_level_stop,
	.show		= service_level_show
};

static void service_level_vm_print(struct seq_file *m,
				   struct service_level *slr)
{
	char *query_buffer, *str;

	query_buffer = kmalloc(1024, GFP_KERNEL | GFP_DMA);
	if (!query_buffer)
		return;
	cpcmd("QUERY CPLEVEL", query_buffer, 1024, NULL);
	str = strchr(query_buffer, '\n');
	if (str)
		*str = 0;
	seq_printf(m, "VM: %s\n", query_buffer);
	kfree(query_buffer);
}

static struct service_level service_level_vm = {
	.seq_print = service_level_vm_print
};

static __init int create_proc_service_level(void)
{
	proc_create_seq("service_levels", 0, NULL, &service_level_seq_ops);
	if (MACHINE_IS_VM)
		register_service_level(&service_level_vm);
	return 0;
}
subsys_initcall(create_proc_service_level);

/*
 * CPU capability might have changed. Therefore recalculate loops_per_jiffy.
 */
void s390_adjust_jiffies(void)
{
	struct sysinfo_1_2_2 *info;
	unsigned long capability;
	struct kernel_fpu fpu;

	info = (void *) get_zeroed_page(GFP_KERNEL);
	if (!info)
		return;

	if (stsi(info, 1, 2, 2) == 0) {
		/*
		 * Major sigh. The cpu capability encoding is "special".
		 * If the first 9 bits of info->capability are 0 then it
		 * is a 32 bit unsigned integer in the range 0 .. 2^23.
		 * If the first 9 bits are != 0 then it is a 32 bit float.
		 * In addition a lower value indicates a proportionally
		 * higher cpu capacity. Bogomips are the other way round.
		 * To get to a halfway suitable number we divide 1e7
		 * by the cpu capability number. Yes, that means a floating
		 * point division ..
		 */
		kernel_fpu_begin(&fpu, KERNEL_FPR);
		asm volatile(
			"	sfpc	%3\n"
			"	l	%0,%1\n"
			"	tmlh	%0,0xff80\n"
			"	jnz	0f\n"
			"	cefbr	%%f2,%0\n"
			"	j	1f\n"
			"0:	le	%%f2,%1\n"
			"1:	cefbr	%%f0,%2\n"
			"	debr	%%f0,%%f2\n"
			"	cgebr	%0,5,%%f0\n"
			: "=&d" (capability)
			: "Q" (info->capability), "d" (10000000), "d" (0)
			: "cc"
			);
		kernel_fpu_end(&fpu, KERNEL_FPR);
	} else
		/*
		 * Really old machine without stsi block for basic
		 * cpu information. Report 42.0 bogomips.
		 */
		capability = 42;
	loops_per_jiffy = capability * (500000/HZ);
	free_page((unsigned long) info);
}

/*
 * calibrate the delay loop
 */
void calibrate_delay(void)
{
	s390_adjust_jiffies();
	/* Print the good old Bogomips line .. */
	printk(KERN_DEBUG "Calibrating delay loop (skipped)... "
	       "%lu.%02lu BogoMIPS preset\n", loops_per_jiffy/(500000/HZ),
	       (loops_per_jiffy/(5000/HZ)) % 100);
}

#ifdef CONFIG_DEBUG_FS

#define STSI_FILE(fc, s1, s2)						       \
static int stsi_open_##fc##_##s1##_##s2(struct inode *inode, struct file *file)\
{									       \
	file->private_data = (void *) get_zeroed_page(GFP_KERNEL);	       \
	if (!file->private_data)					       \
		return -ENOMEM;						       \
	if (stsi(file->private_data, fc, s1, s2)) {			       \
		free_page((unsigned long)file->private_data);		       \
		file->private_data = NULL;				       \
		return -EACCES;						       \
	}								       \
	return nonseekable_open(inode, file);				       \
}									       \
									       \
static const struct file_operations stsi_##fc##_##s1##_##s2##_fs_ops = {       \
	.open		= stsi_open_##fc##_##s1##_##s2,			       \
	.release	= stsi_release,					       \
	.read		= stsi_read,					       \
	.llseek		= no_llseek,					       \
};

static int stsi_release(struct inode *inode, struct file *file)
{
	free_page((unsigned long)file->private_data);
	return 0;
}

static ssize_t stsi_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
	return simple_read_from_buffer(buf, size, ppos, file->private_data, PAGE_SIZE);
}

STSI_FILE( 1, 1, 1);
STSI_FILE( 1, 2, 1);
STSI_FILE( 1, 2, 2);
STSI_FILE( 2, 2, 1);
STSI_FILE( 2, 2, 2);
STSI_FILE( 3, 2, 2);
STSI_FILE(15, 1, 2);
STSI_FILE(15, 1, 3);
STSI_FILE(15, 1, 4);
STSI_FILE(15, 1, 5);
STSI_FILE(15, 1, 6);

struct stsi_file {
	const struct file_operations *fops;
	char *name;
};

static struct stsi_file stsi_file[] __initdata = {
	{.fops = &stsi_1_1_1_fs_ops,  .name =  "1_1_1"},
	{.fops = &stsi_1_2_1_fs_ops,  .name =  "1_2_1"},
	{.fops = &stsi_1_2_2_fs_ops,  .name =  "1_2_2"},
	{.fops = &stsi_2_2_1_fs_ops,  .name =  "2_2_1"},
	{.fops = &stsi_2_2_2_fs_ops,  .name =  "2_2_2"},
	{.fops = &stsi_3_2_2_fs_ops,  .name =  "3_2_2"},
	{.fops = &stsi_15_1_2_fs_ops, .name = "15_1_2"},
	{.fops = &stsi_15_1_3_fs_ops, .name = "15_1_3"},
	{.fops = &stsi_15_1_4_fs_ops, .name = "15_1_4"},
	{.fops = &stsi_15_1_5_fs_ops, .name = "15_1_5"},
	{.fops = &stsi_15_1_6_fs_ops, .name = "15_1_6"},
};

static u8 stsi_0_0_0;

static __init int stsi_init_debugfs(void)
{
	struct dentry *stsi_root;
	struct stsi_file *sf;
	int lvl, i;

	stsi_root = debugfs_create_dir("stsi", arch_debugfs_dir);
	lvl = stsi(NULL, 0, 0, 0);
	if (lvl > 0)
		stsi_0_0_0 = lvl;
	debugfs_create_u8("0_0_0", 0400, stsi_root, &stsi_0_0_0);
	for (i = 0; i < ARRAY_SIZE(stsi_file); i++) {
		sf = &stsi_file[i];
		debugfs_create_file(sf->name, 0400, stsi_root, NULL, sf->fops);
	}
	if (IS_ENABLED(CONFIG_SCHED_TOPOLOGY) && MACHINE_HAS_TOPOLOGY) {
		char link_to[10];

		sprintf(link_to, "15_1_%d", topology_mnest_limit());
		debugfs_create_symlink("topology", stsi_root, link_to);
	}
	return 0;
}
device_initcall(stsi_init_debugfs);

#endif /* CONFIG_DEBUG_FS */