xref: /linux/arch/s390/kernel/sysinfo.c (revision eed4edda910fe34dfae8c6bfbcf57f4593a54295)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright IBM Corp. 2001, 2009
4  *  Author(s): Ulrich Weigand <Ulrich.Weigand@de.ibm.com>,
5  *	       Martin Schwidefsky <schwidefsky@de.ibm.com>,
6  */
7 
8 #include <linux/debugfs.h>
9 #include <linux/kernel.h>
10 #include <linux/mm.h>
11 #include <linux/proc_fs.h>
12 #include <linux/seq_file.h>
13 #include <linux/init.h>
14 #include <linux/delay.h>
15 #include <linux/export.h>
16 #include <linux/slab.h>
17 #include <asm/asm-extable.h>
18 #include <asm/ebcdic.h>
19 #include <asm/debug.h>
20 #include <asm/sysinfo.h>
21 #include <asm/cpcmd.h>
22 #include <asm/topology.h>
23 #include <asm/fpu/api.h>
24 
25 int topology_max_mnest;
26 
27 static inline int __stsi(void *sysinfo, int fc, int sel1, int sel2, int *lvl)
28 {
29 	int r0 = (fc << 28) | sel1;
30 	int rc = 0;
31 
32 	asm volatile(
33 		"	lr	0,%[r0]\n"
34 		"	lr	1,%[r1]\n"
35 		"	stsi	0(%[sysinfo])\n"
36 		"0:	jz	2f\n"
37 		"1:	lhi	%[rc],%[retval]\n"
38 		"2:	lr	%[r0],0\n"
39 		EX_TABLE(0b, 1b)
40 		: [r0] "+d" (r0), [rc] "+d" (rc)
41 		: [r1] "d" (sel2),
42 		  [sysinfo] "a" (sysinfo),
43 		  [retval] "K" (-EOPNOTSUPP)
44 		: "cc", "0", "1", "memory");
45 	*lvl = ((unsigned int) r0) >> 28;
46 	return rc;
47 }
48 
49 /*
50  * stsi - store system information
51  *
52  * Returns the current configuration level if function code 0 was specified.
53  * Otherwise returns 0 on success or a negative value on error.
54  */
55 int stsi(void *sysinfo, int fc, int sel1, int sel2)
56 {
57 	int lvl, rc;
58 
59 	rc = __stsi(sysinfo, fc, sel1, sel2, &lvl);
60 	if (rc)
61 		return rc;
62 	return fc ? 0 : lvl;
63 }
64 EXPORT_SYMBOL(stsi);
65 
66 #ifdef CONFIG_PROC_FS
67 
68 static bool convert_ext_name(unsigned char encoding, char *name, size_t len)
69 {
70 	switch (encoding) {
71 	case 1: /* EBCDIC */
72 		EBCASC(name, len);
73 		break;
74 	case 2:	/* UTF-8 */
75 		break;
76 	default:
77 		return false;
78 	}
79 	return true;
80 }
81 
82 static void stsi_1_1_1(struct seq_file *m, struct sysinfo_1_1_1 *info)
83 {
84 	bool has_var_cap;
85 	int i;
86 
87 	if (stsi(info, 1, 1, 1))
88 		return;
89 	has_var_cap = !!info->model_var_cap[0];
90 	EBCASC(info->manufacturer, sizeof(info->manufacturer));
91 	EBCASC(info->type, sizeof(info->type));
92 	EBCASC(info->model, sizeof(info->model));
93 	EBCASC(info->sequence, sizeof(info->sequence));
94 	EBCASC(info->plant, sizeof(info->plant));
95 	EBCASC(info->model_capacity, sizeof(info->model_capacity));
96 	EBCASC(info->model_perm_cap, sizeof(info->model_perm_cap));
97 	EBCASC(info->model_temp_cap, sizeof(info->model_temp_cap));
98 	if (has_var_cap)
99 		EBCASC(info->model_var_cap, sizeof(info->model_var_cap));
100 	seq_printf(m, "Manufacturer:         %-16.16s\n", info->manufacturer);
101 	seq_printf(m, "Type:                 %-4.4s\n", info->type);
102 	if (info->lic)
103 		seq_printf(m, "LIC Identifier:       %016lx\n", info->lic);
104 	/*
105 	 * Sigh: the model field has been renamed with System z9
106 	 * to model_capacity and a new model field has been added
107 	 * after the plant field. To avoid confusing older programs
108 	 * the "Model:" prints "model_capacity model" or just
109 	 * "model_capacity" if the model string is empty .
110 	 */
111 	seq_printf(m, "Model:                %-16.16s", info->model_capacity);
112 	if (info->model[0] != '\0')
113 		seq_printf(m, " %-16.16s", info->model);
114 	seq_putc(m, '\n');
115 	seq_printf(m, "Sequence Code:        %-16.16s\n", info->sequence);
116 	seq_printf(m, "Plant:                %-4.4s\n", info->plant);
117 	seq_printf(m, "Model Capacity:       %-16.16s %08u\n",
118 		   info->model_capacity, info->model_cap_rating);
119 	if (info->model_perm_cap_rating)
120 		seq_printf(m, "Model Perm. Capacity: %-16.16s %08u\n",
121 			   info->model_perm_cap,
122 			   info->model_perm_cap_rating);
123 	if (info->model_temp_cap_rating)
124 		seq_printf(m, "Model Temp. Capacity: %-16.16s %08u\n",
125 			   info->model_temp_cap,
126 			   info->model_temp_cap_rating);
127 	if (has_var_cap && info->model_var_cap_rating)
128 		seq_printf(m, "Model Var. Capacity:  %-16.16s %08u\n",
129 			   info->model_var_cap,
130 			   info->model_var_cap_rating);
131 	if (info->ncr)
132 		seq_printf(m, "Nominal Cap. Rating:  %08u\n", info->ncr);
133 	if (info->npr)
134 		seq_printf(m, "Nominal Perm. Rating: %08u\n", info->npr);
135 	if (info->ntr)
136 		seq_printf(m, "Nominal Temp. Rating: %08u\n", info->ntr);
137 	if (has_var_cap && info->nvr)
138 		seq_printf(m, "Nominal Var. Rating:  %08u\n", info->nvr);
139 	if (info->cai) {
140 		seq_printf(m, "Capacity Adj. Ind.:   %d\n", info->cai);
141 		seq_printf(m, "Capacity Ch. Reason:  %d\n", info->ccr);
142 		seq_printf(m, "Capacity Transient:   %d\n", info->t);
143 	}
144 	if (info->p) {
145 		for (i = 1; i <= ARRAY_SIZE(info->typepct); i++) {
146 			seq_printf(m, "Type %d Percentage:    %d\n",
147 				   i, info->typepct[i - 1]);
148 		}
149 	}
150 }
151 
152 static void stsi_15_1_x(struct seq_file *m, struct sysinfo_15_1_x *info)
153 {
154 	int i;
155 
156 	seq_putc(m, '\n');
157 	if (!MACHINE_HAS_TOPOLOGY)
158 		return;
159 	if (stsi(info, 15, 1, topology_max_mnest))
160 		return;
161 	seq_printf(m, "CPU Topology HW:     ");
162 	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
163 		seq_printf(m, " %d", info->mag[i]);
164 	seq_putc(m, '\n');
165 #ifdef CONFIG_SCHED_TOPOLOGY
166 	store_topology(info);
167 	seq_printf(m, "CPU Topology SW:     ");
168 	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
169 		seq_printf(m, " %d", info->mag[i]);
170 	seq_putc(m, '\n');
171 #endif
172 }
173 
174 static void stsi_1_2_2(struct seq_file *m, struct sysinfo_1_2_2 *info)
175 {
176 	struct sysinfo_1_2_2_extension *ext;
177 	int i;
178 
179 	if (stsi(info, 1, 2, 2))
180 		return;
181 	ext = (struct sysinfo_1_2_2_extension *)
182 		((unsigned long) info + info->acc_offset);
183 	seq_printf(m, "CPUs Total:           %d\n", info->cpus_total);
184 	seq_printf(m, "CPUs Configured:      %d\n", info->cpus_configured);
185 	seq_printf(m, "CPUs Standby:         %d\n", info->cpus_standby);
186 	seq_printf(m, "CPUs Reserved:        %d\n", info->cpus_reserved);
187 	if (info->mt_installed) {
188 		seq_printf(m, "CPUs G-MTID:          %d\n", info->mt_gtid);
189 		seq_printf(m, "CPUs S-MTID:          %d\n", info->mt_stid);
190 	}
191 	/*
192 	 * Sigh 2. According to the specification the alternate
193 	 * capability field is a 32 bit floating point number
194 	 * if the higher order 8 bits are not zero. Printing
195 	 * a floating point number in the kernel is a no-no,
196 	 * always print the number as 32 bit unsigned integer.
197 	 * The user-space needs to know about the strange
198 	 * encoding of the alternate cpu capability.
199 	 */
200 	seq_printf(m, "Capability:           %u", info->capability);
201 	if (info->format == 1)
202 		seq_printf(m, " %u", ext->alt_capability);
203 	seq_putc(m, '\n');
204 	if (info->nominal_cap)
205 		seq_printf(m, "Nominal Capability:   %d\n", info->nominal_cap);
206 	if (info->secondary_cap)
207 		seq_printf(m, "Secondary Capability: %d\n", info->secondary_cap);
208 	for (i = 2; i <= info->cpus_total; i++) {
209 		seq_printf(m, "Adjustment %02d-way:    %u",
210 			   i, info->adjustment[i-2]);
211 		if (info->format == 1)
212 			seq_printf(m, " %u", ext->alt_adjustment[i-2]);
213 		seq_putc(m, '\n');
214 	}
215 }
216 
217 static void stsi_2_2_2(struct seq_file *m, struct sysinfo_2_2_2 *info)
218 {
219 	if (stsi(info, 2, 2, 2))
220 		return;
221 	EBCASC(info->name, sizeof(info->name));
222 	seq_putc(m, '\n');
223 	seq_printf(m, "LPAR Number:          %d\n", info->lpar_number);
224 	seq_printf(m, "LPAR Characteristics: ");
225 	if (info->characteristics & LPAR_CHAR_DEDICATED)
226 		seq_printf(m, "Dedicated ");
227 	if (info->characteristics & LPAR_CHAR_SHARED)
228 		seq_printf(m, "Shared ");
229 	if (info->characteristics & LPAR_CHAR_LIMITED)
230 		seq_printf(m, "Limited ");
231 	seq_putc(m, '\n');
232 	seq_printf(m, "LPAR Name:            %-8.8s\n", info->name);
233 	seq_printf(m, "LPAR Adjustment:      %d\n", info->caf);
234 	seq_printf(m, "LPAR CPUs Total:      %d\n", info->cpus_total);
235 	seq_printf(m, "LPAR CPUs Configured: %d\n", info->cpus_configured);
236 	seq_printf(m, "LPAR CPUs Standby:    %d\n", info->cpus_standby);
237 	seq_printf(m, "LPAR CPUs Reserved:   %d\n", info->cpus_reserved);
238 	seq_printf(m, "LPAR CPUs Dedicated:  %d\n", info->cpus_dedicated);
239 	seq_printf(m, "LPAR CPUs Shared:     %d\n", info->cpus_shared);
240 	if (info->mt_installed) {
241 		seq_printf(m, "LPAR CPUs G-MTID:     %d\n", info->mt_gtid);
242 		seq_printf(m, "LPAR CPUs S-MTID:     %d\n", info->mt_stid);
243 		seq_printf(m, "LPAR CPUs PS-MTID:    %d\n", info->mt_psmtid);
244 	}
245 	if (convert_ext_name(info->vsne, info->ext_name, sizeof(info->ext_name))) {
246 		seq_printf(m, "LPAR Extended Name:   %-.256s\n", info->ext_name);
247 		seq_printf(m, "LPAR UUID:            %pUb\n", &info->uuid);
248 	}
249 }
250 
251 static void print_ext_name(struct seq_file *m, int lvl,
252 			   struct sysinfo_3_2_2 *info)
253 {
254 	size_t len = sizeof(info->ext_names[lvl]);
255 
256 	if (!convert_ext_name(info->vm[lvl].evmne, info->ext_names[lvl], len))
257 		return;
258 	seq_printf(m, "VM%02d Extended Name:   %-.256s\n", lvl,
259 		   info->ext_names[lvl]);
260 }
261 
262 static void print_uuid(struct seq_file *m, int i, struct sysinfo_3_2_2 *info)
263 {
264 	if (uuid_is_null(&info->vm[i].uuid))
265 		return;
266 	seq_printf(m, "VM%02d UUID:            %pUb\n", i, &info->vm[i].uuid);
267 }
268 
269 static void stsi_3_2_2(struct seq_file *m, struct sysinfo_3_2_2 *info)
270 {
271 	int i;
272 
273 	if (stsi(info, 3, 2, 2))
274 		return;
275 	for (i = 0; i < info->count; i++) {
276 		EBCASC(info->vm[i].name, sizeof(info->vm[i].name));
277 		EBCASC(info->vm[i].cpi, sizeof(info->vm[i].cpi));
278 		seq_putc(m, '\n');
279 		seq_printf(m, "VM%02d Name:            %-8.8s\n", i, info->vm[i].name);
280 		seq_printf(m, "VM%02d Control Program: %-16.16s\n", i, info->vm[i].cpi);
281 		seq_printf(m, "VM%02d Adjustment:      %d\n", i, info->vm[i].caf);
282 		seq_printf(m, "VM%02d CPUs Total:      %d\n", i, info->vm[i].cpus_total);
283 		seq_printf(m, "VM%02d CPUs Configured: %d\n", i, info->vm[i].cpus_configured);
284 		seq_printf(m, "VM%02d CPUs Standby:    %d\n", i, info->vm[i].cpus_standby);
285 		seq_printf(m, "VM%02d CPUs Reserved:   %d\n", i, info->vm[i].cpus_reserved);
286 		print_ext_name(m, i, info);
287 		print_uuid(m, i, info);
288 	}
289 }
290 
291 static int sysinfo_show(struct seq_file *m, void *v)
292 {
293 	void *info = (void *)get_zeroed_page(GFP_KERNEL);
294 	int level;
295 
296 	if (!info)
297 		return 0;
298 	level = stsi(NULL, 0, 0, 0);
299 	if (level >= 1)
300 		stsi_1_1_1(m, info);
301 	if (level >= 1)
302 		stsi_15_1_x(m, info);
303 	if (level >= 1)
304 		stsi_1_2_2(m, info);
305 	if (level >= 2)
306 		stsi_2_2_2(m, info);
307 	if (level >= 3)
308 		stsi_3_2_2(m, info);
309 	free_page((unsigned long)info);
310 	return 0;
311 }
312 
313 static int __init sysinfo_create_proc(void)
314 {
315 	proc_create_single("sysinfo", 0444, NULL, sysinfo_show);
316 	return 0;
317 }
318 device_initcall(sysinfo_create_proc);
319 
320 #endif /* CONFIG_PROC_FS */
321 
322 /*
323  * Service levels interface.
324  */
325 
326 static DECLARE_RWSEM(service_level_sem);
327 static LIST_HEAD(service_level_list);
328 
329 int register_service_level(struct service_level *slr)
330 {
331 	struct service_level *ptr;
332 
333 	down_write(&service_level_sem);
334 	list_for_each_entry(ptr, &service_level_list, list)
335 		if (ptr == slr) {
336 			up_write(&service_level_sem);
337 			return -EEXIST;
338 		}
339 	list_add_tail(&slr->list, &service_level_list);
340 	up_write(&service_level_sem);
341 	return 0;
342 }
343 EXPORT_SYMBOL(register_service_level);
344 
345 int unregister_service_level(struct service_level *slr)
346 {
347 	struct service_level *ptr, *next;
348 	int rc = -ENOENT;
349 
350 	down_write(&service_level_sem);
351 	list_for_each_entry_safe(ptr, next, &service_level_list, list) {
352 		if (ptr != slr)
353 			continue;
354 		list_del(&ptr->list);
355 		rc = 0;
356 		break;
357 	}
358 	up_write(&service_level_sem);
359 	return rc;
360 }
361 EXPORT_SYMBOL(unregister_service_level);
362 
363 static void *service_level_start(struct seq_file *m, loff_t *pos)
364 {
365 	down_read(&service_level_sem);
366 	return seq_list_start(&service_level_list, *pos);
367 }
368 
369 static void *service_level_next(struct seq_file *m, void *p, loff_t *pos)
370 {
371 	return seq_list_next(p, &service_level_list, pos);
372 }
373 
374 static void service_level_stop(struct seq_file *m, void *p)
375 {
376 	up_read(&service_level_sem);
377 }
378 
379 static int service_level_show(struct seq_file *m, void *p)
380 {
381 	struct service_level *slr;
382 
383 	slr = list_entry(p, struct service_level, list);
384 	slr->seq_print(m, slr);
385 	return 0;
386 }
387 
388 static const struct seq_operations service_level_seq_ops = {
389 	.start		= service_level_start,
390 	.next		= service_level_next,
391 	.stop		= service_level_stop,
392 	.show		= service_level_show
393 };
394 
395 static void service_level_vm_print(struct seq_file *m,
396 				   struct service_level *slr)
397 {
398 	char *query_buffer, *str;
399 
400 	query_buffer = kmalloc(1024, GFP_KERNEL | GFP_DMA);
401 	if (!query_buffer)
402 		return;
403 	cpcmd("QUERY CPLEVEL", query_buffer, 1024, NULL);
404 	str = strchr(query_buffer, '\n');
405 	if (str)
406 		*str = 0;
407 	seq_printf(m, "VM: %s\n", query_buffer);
408 	kfree(query_buffer);
409 }
410 
411 static struct service_level service_level_vm = {
412 	.seq_print = service_level_vm_print
413 };
414 
415 static __init int create_proc_service_level(void)
416 {
417 	proc_create_seq("service_levels", 0, NULL, &service_level_seq_ops);
418 	if (MACHINE_IS_VM)
419 		register_service_level(&service_level_vm);
420 	return 0;
421 }
422 subsys_initcall(create_proc_service_level);
423 
424 /*
425  * CPU capability might have changed. Therefore recalculate loops_per_jiffy.
426  */
427 void s390_adjust_jiffies(void)
428 {
429 	struct sysinfo_1_2_2 *info;
430 	unsigned long capability;
431 	struct kernel_fpu fpu;
432 
433 	info = (void *) get_zeroed_page(GFP_KERNEL);
434 	if (!info)
435 		return;
436 
437 	if (stsi(info, 1, 2, 2) == 0) {
438 		/*
439 		 * Major sigh. The cpu capability encoding is "special".
440 		 * If the first 9 bits of info->capability are 0 then it
441 		 * is a 32 bit unsigned integer in the range 0 .. 2^23.
442 		 * If the first 9 bits are != 0 then it is a 32 bit float.
443 		 * In addition a lower value indicates a proportionally
444 		 * higher cpu capacity. Bogomips are the other way round.
445 		 * To get to a halfway suitable number we divide 1e7
446 		 * by the cpu capability number. Yes, that means a floating
447 		 * point division ..
448 		 */
449 		kernel_fpu_begin(&fpu, KERNEL_FPR);
450 		asm volatile(
451 			"	sfpc	%3\n"
452 			"	l	%0,%1\n"
453 			"	tmlh	%0,0xff80\n"
454 			"	jnz	0f\n"
455 			"	cefbr	%%f2,%0\n"
456 			"	j	1f\n"
457 			"0:	le	%%f2,%1\n"
458 			"1:	cefbr	%%f0,%2\n"
459 			"	debr	%%f0,%%f2\n"
460 			"	cgebr	%0,5,%%f0\n"
461 			: "=&d" (capability)
462 			: "Q" (info->capability), "d" (10000000), "d" (0)
463 			: "cc"
464 			);
465 		kernel_fpu_end(&fpu, KERNEL_FPR);
466 	} else
467 		/*
468 		 * Really old machine without stsi block for basic
469 		 * cpu information. Report 42.0 bogomips.
470 		 */
471 		capability = 42;
472 	loops_per_jiffy = capability * (500000/HZ);
473 	free_page((unsigned long) info);
474 }
475 
476 /*
477  * calibrate the delay loop
478  */
479 void calibrate_delay(void)
480 {
481 	s390_adjust_jiffies();
482 	/* Print the good old Bogomips line .. */
483 	printk(KERN_DEBUG "Calibrating delay loop (skipped)... "
484 	       "%lu.%02lu BogoMIPS preset\n", loops_per_jiffy/(500000/HZ),
485 	       (loops_per_jiffy/(5000/HZ)) % 100);
486 }
487 
488 #ifdef CONFIG_DEBUG_FS
489 
490 #define STSI_FILE(fc, s1, s2)						       \
491 static int stsi_open_##fc##_##s1##_##s2(struct inode *inode, struct file *file)\
492 {									       \
493 	file->private_data = (void *) get_zeroed_page(GFP_KERNEL);	       \
494 	if (!file->private_data)					       \
495 		return -ENOMEM;						       \
496 	if (stsi(file->private_data, fc, s1, s2)) {			       \
497 		free_page((unsigned long)file->private_data);		       \
498 		file->private_data = NULL;				       \
499 		return -EACCES;						       \
500 	}								       \
501 	return nonseekable_open(inode, file);				       \
502 }									       \
503 									       \
504 static const struct file_operations stsi_##fc##_##s1##_##s2##_fs_ops = {       \
505 	.open		= stsi_open_##fc##_##s1##_##s2,			       \
506 	.release	= stsi_release,					       \
507 	.read		= stsi_read,					       \
508 	.llseek		= no_llseek,					       \
509 };
510 
511 static int stsi_release(struct inode *inode, struct file *file)
512 {
513 	free_page((unsigned long)file->private_data);
514 	return 0;
515 }
516 
517 static ssize_t stsi_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
518 {
519 	return simple_read_from_buffer(buf, size, ppos, file->private_data, PAGE_SIZE);
520 }
521 
522 STSI_FILE( 1, 1, 1);
523 STSI_FILE( 1, 2, 1);
524 STSI_FILE( 1, 2, 2);
525 STSI_FILE( 2, 2, 1);
526 STSI_FILE( 2, 2, 2);
527 STSI_FILE( 3, 2, 2);
528 STSI_FILE(15, 1, 2);
529 STSI_FILE(15, 1, 3);
530 STSI_FILE(15, 1, 4);
531 STSI_FILE(15, 1, 5);
532 STSI_FILE(15, 1, 6);
533 
534 struct stsi_file {
535 	const struct file_operations *fops;
536 	char *name;
537 };
538 
539 static struct stsi_file stsi_file[] __initdata = {
540 	{.fops = &stsi_1_1_1_fs_ops,  .name =  "1_1_1"},
541 	{.fops = &stsi_1_2_1_fs_ops,  .name =  "1_2_1"},
542 	{.fops = &stsi_1_2_2_fs_ops,  .name =  "1_2_2"},
543 	{.fops = &stsi_2_2_1_fs_ops,  .name =  "2_2_1"},
544 	{.fops = &stsi_2_2_2_fs_ops,  .name =  "2_2_2"},
545 	{.fops = &stsi_3_2_2_fs_ops,  .name =  "3_2_2"},
546 	{.fops = &stsi_15_1_2_fs_ops, .name = "15_1_2"},
547 	{.fops = &stsi_15_1_3_fs_ops, .name = "15_1_3"},
548 	{.fops = &stsi_15_1_4_fs_ops, .name = "15_1_4"},
549 	{.fops = &stsi_15_1_5_fs_ops, .name = "15_1_5"},
550 	{.fops = &stsi_15_1_6_fs_ops, .name = "15_1_6"},
551 };
552 
553 static u8 stsi_0_0_0;
554 
555 static __init int stsi_init_debugfs(void)
556 {
557 	struct dentry *stsi_root;
558 	struct stsi_file *sf;
559 	int lvl, i;
560 
561 	stsi_root = debugfs_create_dir("stsi", arch_debugfs_dir);
562 	lvl = stsi(NULL, 0, 0, 0);
563 	if (lvl > 0)
564 		stsi_0_0_0 = lvl;
565 	debugfs_create_u8("0_0_0", 0400, stsi_root, &stsi_0_0_0);
566 	for (i = 0; i < ARRAY_SIZE(stsi_file); i++) {
567 		sf = &stsi_file[i];
568 		debugfs_create_file(sf->name, 0400, stsi_root, NULL, sf->fops);
569 	}
570 	if (IS_ENABLED(CONFIG_SCHED_TOPOLOGY) && MACHINE_HAS_TOPOLOGY) {
571 		char link_to[10];
572 
573 		sprintf(link_to, "15_1_%d", topology_mnest_limit());
574 		debugfs_create_symlink("topology", stsi_root, link_to);
575 	}
576 	return 0;
577 }
578 device_initcall(stsi_init_debugfs);
579 
580 #endif /* CONFIG_DEBUG_FS */
581