xref: /openbmc/linux/arch/s390/hypfs/hypfs_diag.c (revision b78412b8)
1 /*
2  *    Hypervisor filesystem for Linux on s390. Diag 204 and 224
3  *    implementation.
4  *
5  *    Copyright IBM Corp. 2006, 2008
6  *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
7  */
8 
9 #define KMSG_COMPONENT "hypfs"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11 
12 #include <linux/types.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/vmalloc.h>
17 #include <linux/mm.h>
18 #include <asm/diag.h>
19 #include <asm/ebcdic.h>
20 #include "hypfs.h"
21 
22 #define TMP_SIZE 64		/* size of temporary buffers */
23 
24 #define DBFS_D204_HDR_VERSION	0
25 
26 static char *diag224_cpu_names;			/* diag 224 name table */
27 static enum diag204_sc diag204_store_sc;	/* used subcode for store */
28 static enum diag204_format diag204_info_type;	/* used diag 204 data format */
29 
30 static void *diag204_buf;		/* 4K aligned buffer for diag204 data */
31 static void *diag204_buf_vmalloc;	/* vmalloc pointer for diag204 data */
32 static int diag204_buf_pages;		/* number of pages for diag204 data */
33 
34 static struct dentry *dbfs_d204_file;
35 
36 /*
37  * DIAG 204 member access functions.
38  *
39  * Since we have two different diag 204 data formats for old and new s390
40  * machines, we do not access the structs directly, but use getter functions for
41  * each struct member instead. This should make the code more readable.
42  */
43 
44 /* Time information block */
45 
46 static inline int info_blk_hdr__size(enum diag204_format type)
47 {
48 	if (type == DIAG204_INFO_SIMPLE)
49 		return sizeof(struct diag204_info_blk_hdr);
50 	else /* DIAG204_INFO_EXT */
51 		return sizeof(struct diag204_x_info_blk_hdr);
52 }
53 
54 static inline __u8 info_blk_hdr__npar(enum diag204_format type, void *hdr)
55 {
56 	if (type == DIAG204_INFO_SIMPLE)
57 		return ((struct diag204_info_blk_hdr *)hdr)->npar;
58 	else /* DIAG204_INFO_EXT */
59 		return ((struct diag204_x_info_blk_hdr *)hdr)->npar;
60 }
61 
62 static inline __u8 info_blk_hdr__flags(enum diag204_format type, void *hdr)
63 {
64 	if (type == DIAG204_INFO_SIMPLE)
65 		return ((struct diag204_info_blk_hdr *)hdr)->flags;
66 	else /* DIAG204_INFO_EXT */
67 		return ((struct diag204_x_info_blk_hdr *)hdr)->flags;
68 }
69 
70 static inline __u16 info_blk_hdr__pcpus(enum diag204_format type, void *hdr)
71 {
72 	if (type == DIAG204_INFO_SIMPLE)
73 		return ((struct diag204_info_blk_hdr *)hdr)->phys_cpus;
74 	else /* DIAG204_INFO_EXT */
75 		return ((struct diag204_x_info_blk_hdr *)hdr)->phys_cpus;
76 }
77 
78 /* Partition header */
79 
80 static inline int part_hdr__size(enum diag204_format type)
81 {
82 	if (type == DIAG204_INFO_SIMPLE)
83 		return sizeof(struct diag204_part_hdr);
84 	else /* DIAG204_INFO_EXT */
85 		return sizeof(struct diag204_x_part_hdr);
86 }
87 
88 static inline __u8 part_hdr__rcpus(enum diag204_format type, void *hdr)
89 {
90 	if (type == DIAG204_INFO_SIMPLE)
91 		return ((struct diag204_part_hdr *)hdr)->cpus;
92 	else /* DIAG204_INFO_EXT */
93 		return ((struct diag204_x_part_hdr *)hdr)->rcpus;
94 }
95 
96 static inline void part_hdr__part_name(enum diag204_format type, void *hdr,
97 				       char *name)
98 {
99 	if (type == DIAG204_INFO_SIMPLE)
100 		memcpy(name, ((struct diag204_part_hdr *)hdr)->part_name,
101 		       DIAG204_LPAR_NAME_LEN);
102 	else /* DIAG204_INFO_EXT */
103 		memcpy(name, ((struct diag204_x_part_hdr *)hdr)->part_name,
104 		       DIAG204_LPAR_NAME_LEN);
105 	EBCASC(name, DIAG204_LPAR_NAME_LEN);
106 	name[DIAG204_LPAR_NAME_LEN] = 0;
107 	strim(name);
108 }
109 
110 /* CPU info block */
111 
112 static inline int cpu_info__size(enum diag204_format type)
113 {
114 	if (type == DIAG204_INFO_SIMPLE)
115 		return sizeof(struct diag204_cpu_info);
116 	else /* DIAG204_INFO_EXT */
117 		return sizeof(struct diag204_x_cpu_info);
118 }
119 
120 static inline __u8 cpu_info__ctidx(enum diag204_format type, void *hdr)
121 {
122 	if (type == DIAG204_INFO_SIMPLE)
123 		return ((struct diag204_cpu_info *)hdr)->ctidx;
124 	else /* DIAG204_INFO_EXT */
125 		return ((struct diag204_x_cpu_info *)hdr)->ctidx;
126 }
127 
128 static inline __u16 cpu_info__cpu_addr(enum diag204_format type, void *hdr)
129 {
130 	if (type == DIAG204_INFO_SIMPLE)
131 		return ((struct diag204_cpu_info *)hdr)->cpu_addr;
132 	else /* DIAG204_INFO_EXT */
133 		return ((struct diag204_x_cpu_info *)hdr)->cpu_addr;
134 }
135 
136 static inline __u64 cpu_info__acc_time(enum diag204_format type, void *hdr)
137 {
138 	if (type == DIAG204_INFO_SIMPLE)
139 		return ((struct diag204_cpu_info *)hdr)->acc_time;
140 	else /* DIAG204_INFO_EXT */
141 		return ((struct diag204_x_cpu_info *)hdr)->acc_time;
142 }
143 
144 static inline __u64 cpu_info__lp_time(enum diag204_format type, void *hdr)
145 {
146 	if (type == DIAG204_INFO_SIMPLE)
147 		return ((struct diag204_cpu_info *)hdr)->lp_time;
148 	else /* DIAG204_INFO_EXT */
149 		return ((struct diag204_x_cpu_info *)hdr)->lp_time;
150 }
151 
152 static inline __u64 cpu_info__online_time(enum diag204_format type, void *hdr)
153 {
154 	if (type == DIAG204_INFO_SIMPLE)
155 		return 0;	/* online_time not available in simple info */
156 	else /* DIAG204_INFO_EXT */
157 		return ((struct diag204_x_cpu_info *)hdr)->online_time;
158 }
159 
160 /* Physical header */
161 
162 static inline int phys_hdr__size(enum diag204_format type)
163 {
164 	if (type == DIAG204_INFO_SIMPLE)
165 		return sizeof(struct diag204_phys_hdr);
166 	else /* DIAG204_INFO_EXT */
167 		return sizeof(struct diag204_x_phys_hdr);
168 }
169 
170 static inline __u8 phys_hdr__cpus(enum diag204_format type, void *hdr)
171 {
172 	if (type == DIAG204_INFO_SIMPLE)
173 		return ((struct diag204_phys_hdr *)hdr)->cpus;
174 	else /* DIAG204_INFO_EXT */
175 		return ((struct diag204_x_phys_hdr *)hdr)->cpus;
176 }
177 
178 /* Physical CPU info block */
179 
180 static inline int phys_cpu__size(enum diag204_format type)
181 {
182 	if (type == DIAG204_INFO_SIMPLE)
183 		return sizeof(struct diag204_phys_cpu);
184 	else /* DIAG204_INFO_EXT */
185 		return sizeof(struct diag204_x_phys_cpu);
186 }
187 
188 static inline __u16 phys_cpu__cpu_addr(enum diag204_format type, void *hdr)
189 {
190 	if (type == DIAG204_INFO_SIMPLE)
191 		return ((struct diag204_phys_cpu *)hdr)->cpu_addr;
192 	else /* DIAG204_INFO_EXT */
193 		return ((struct diag204_x_phys_cpu *)hdr)->cpu_addr;
194 }
195 
196 static inline __u64 phys_cpu__mgm_time(enum diag204_format type, void *hdr)
197 {
198 	if (type == DIAG204_INFO_SIMPLE)
199 		return ((struct diag204_phys_cpu *)hdr)->mgm_time;
200 	else /* DIAG204_INFO_EXT */
201 		return ((struct diag204_x_phys_cpu *)hdr)->mgm_time;
202 }
203 
204 static inline __u64 phys_cpu__ctidx(enum diag204_format type, void *hdr)
205 {
206 	if (type == DIAG204_INFO_SIMPLE)
207 		return ((struct diag204_phys_cpu *)hdr)->ctidx;
208 	else /* DIAG204_INFO_EXT */
209 		return ((struct diag204_x_phys_cpu *)hdr)->ctidx;
210 }
211 
212 /* Diagnose 204 functions */
213 /*
214  * For the old diag subcode 4 with simple data format we have to use real
215  * memory. If we use subcode 6 or 7 with extended data format, we can (and
216  * should) use vmalloc, since we need a lot of memory in that case. Currently
217  * up to 93 pages!
218  */
219 
220 static void diag204_free_buffer(void)
221 {
222 	if (!diag204_buf)
223 		return;
224 	if (diag204_buf_vmalloc) {
225 		vfree(diag204_buf_vmalloc);
226 		diag204_buf_vmalloc = NULL;
227 	} else {
228 		free_pages((unsigned long) diag204_buf, 0);
229 	}
230 	diag204_buf = NULL;
231 }
232 
233 static void *page_align_ptr(void *ptr)
234 {
235 	return (void *) PAGE_ALIGN((unsigned long) ptr);
236 }
237 
238 static void *diag204_alloc_vbuf(int pages)
239 {
240 	/* The buffer has to be page aligned! */
241 	diag204_buf_vmalloc = vmalloc(PAGE_SIZE * (pages + 1));
242 	if (!diag204_buf_vmalloc)
243 		return ERR_PTR(-ENOMEM);
244 	diag204_buf = page_align_ptr(diag204_buf_vmalloc);
245 	diag204_buf_pages = pages;
246 	return diag204_buf;
247 }
248 
249 static void *diag204_alloc_rbuf(void)
250 {
251 	diag204_buf = (void*)__get_free_pages(GFP_KERNEL,0);
252 	if (!diag204_buf)
253 		return ERR_PTR(-ENOMEM);
254 	diag204_buf_pages = 1;
255 	return diag204_buf;
256 }
257 
258 static void *diag204_get_buffer(enum diag204_format fmt, int *pages)
259 {
260 	if (diag204_buf) {
261 		*pages = diag204_buf_pages;
262 		return diag204_buf;
263 	}
264 	if (fmt == DIAG204_INFO_SIMPLE) {
265 		*pages = 1;
266 		return diag204_alloc_rbuf();
267 	} else {/* DIAG204_INFO_EXT */
268 		*pages = diag204((unsigned long)DIAG204_SUBC_RSI |
269 				 (unsigned long)DIAG204_INFO_EXT, 0, NULL);
270 		if (*pages <= 0)
271 			return ERR_PTR(-ENOSYS);
272 		else
273 			return diag204_alloc_vbuf(*pages);
274 	}
275 }
276 
277 /*
278  * diag204_probe() has to find out, which type of diagnose 204 implementation
279  * we have on our machine. Currently there are three possible scanarios:
280  *   - subcode 4   + simple data format (only one page)
281  *   - subcode 4-6 + extended data format
282  *   - subcode 4-7 + extended data format
283  *
284  * Subcode 5 is used to retrieve the size of the data, provided by subcodes
285  * 6 and 7. Subcode 7 basically has the same function as subcode 6. In addition
286  * to subcode 6 it provides also information about secondary cpus.
287  * In order to get as much information as possible, we first try
288  * subcode 7, then 6 and if both fail, we use subcode 4.
289  */
290 
291 static int diag204_probe(void)
292 {
293 	void *buf;
294 	int pages, rc;
295 
296 	buf = diag204_get_buffer(DIAG204_INFO_EXT, &pages);
297 	if (!IS_ERR(buf)) {
298 		if (diag204((unsigned long)DIAG204_SUBC_STIB7 |
299 			    (unsigned long)DIAG204_INFO_EXT, pages, buf) >= 0) {
300 			diag204_store_sc = DIAG204_SUBC_STIB7;
301 			diag204_info_type = DIAG204_INFO_EXT;
302 			goto out;
303 		}
304 		if (diag204((unsigned long)DIAG204_SUBC_STIB6 |
305 			    (unsigned long)DIAG204_INFO_EXT, pages, buf) >= 0) {
306 			diag204_store_sc = DIAG204_SUBC_STIB6;
307 			diag204_info_type = DIAG204_INFO_EXT;
308 			goto out;
309 		}
310 		diag204_free_buffer();
311 	}
312 
313 	/* subcodes 6 and 7 failed, now try subcode 4 */
314 
315 	buf = diag204_get_buffer(DIAG204_INFO_SIMPLE, &pages);
316 	if (IS_ERR(buf)) {
317 		rc = PTR_ERR(buf);
318 		goto fail_alloc;
319 	}
320 	if (diag204((unsigned long)DIAG204_SUBC_STIB4 |
321 		    (unsigned long)DIAG204_INFO_SIMPLE, pages, buf) >= 0) {
322 		diag204_store_sc = DIAG204_SUBC_STIB4;
323 		diag204_info_type = DIAG204_INFO_SIMPLE;
324 		goto out;
325 	} else {
326 		rc = -ENOSYS;
327 		goto fail_store;
328 	}
329 out:
330 	rc = 0;
331 fail_store:
332 	diag204_free_buffer();
333 fail_alloc:
334 	return rc;
335 }
336 
337 static int diag204_do_store(void *buf, int pages)
338 {
339 	int rc;
340 
341 	rc = diag204((unsigned long) diag204_store_sc |
342 		     (unsigned long) diag204_info_type, pages, buf);
343 	return rc < 0 ? -ENOSYS : 0;
344 }
345 
346 static void *diag204_store(void)
347 {
348 	void *buf;
349 	int pages, rc;
350 
351 	buf = diag204_get_buffer(diag204_info_type, &pages);
352 	if (IS_ERR(buf))
353 		goto out;
354 	rc = diag204_do_store(buf, pages);
355 	if (rc)
356 		return ERR_PTR(rc);
357 out:
358 	return buf;
359 }
360 
361 /* Diagnose 224 functions */
362 
363 static int diag224_get_name_table(void)
364 {
365 	/* memory must be below 2GB */
366 	diag224_cpu_names = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
367 	if (!diag224_cpu_names)
368 		return -ENOMEM;
369 	if (diag224(diag224_cpu_names)) {
370 		free_page((unsigned long) diag224_cpu_names);
371 		return -EOPNOTSUPP;
372 	}
373 	EBCASC(diag224_cpu_names + 16, (*diag224_cpu_names + 1) * 16);
374 	return 0;
375 }
376 
377 static void diag224_delete_name_table(void)
378 {
379 	free_page((unsigned long) diag224_cpu_names);
380 }
381 
382 static int diag224_idx2name(int index, char *name)
383 {
384 	memcpy(name, diag224_cpu_names + ((index + 1) * DIAG204_CPU_NAME_LEN),
385 	       DIAG204_CPU_NAME_LEN);
386 	name[DIAG204_CPU_NAME_LEN] = 0;
387 	strim(name);
388 	return 0;
389 }
390 
391 struct dbfs_d204_hdr {
392 	u64	len;		/* Length of d204 buffer without header */
393 	u16	version;	/* Version of header */
394 	u8	sc;		/* Used subcode */
395 	char	reserved[53];
396 } __attribute__ ((packed));
397 
398 struct dbfs_d204 {
399 	struct dbfs_d204_hdr	hdr;	/* 64 byte header */
400 	char			buf[];	/* d204 buffer */
401 } __attribute__ ((packed));
402 
403 static int dbfs_d204_create(void **data, void **data_free_ptr, size_t *size)
404 {
405 	struct dbfs_d204 *d204;
406 	int rc, buf_size;
407 	void *base;
408 
409 	buf_size = PAGE_SIZE * (diag204_buf_pages + 1) + sizeof(d204->hdr);
410 	base = vzalloc(buf_size);
411 	if (!base)
412 		return -ENOMEM;
413 	d204 = page_align_ptr(base + sizeof(d204->hdr)) - sizeof(d204->hdr);
414 	rc = diag204_do_store(d204->buf, diag204_buf_pages);
415 	if (rc) {
416 		vfree(base);
417 		return rc;
418 	}
419 	d204->hdr.version = DBFS_D204_HDR_VERSION;
420 	d204->hdr.len = PAGE_SIZE * diag204_buf_pages;
421 	d204->hdr.sc = diag204_store_sc;
422 	*data = d204;
423 	*data_free_ptr = base;
424 	*size = d204->hdr.len + sizeof(struct dbfs_d204_hdr);
425 	return 0;
426 }
427 
428 static struct hypfs_dbfs_file dbfs_file_d204 = {
429 	.name		= "diag_204",
430 	.data_create	= dbfs_d204_create,
431 	.data_free	= vfree,
432 };
433 
434 __init int hypfs_diag_init(void)
435 {
436 	int rc;
437 
438 	if (diag204_probe()) {
439 		pr_err("The hardware system does not support hypfs\n");
440 		return -ENODATA;
441 	}
442 	if (diag204_info_type == DIAG204_INFO_EXT) {
443 		rc = hypfs_dbfs_create_file(&dbfs_file_d204);
444 		if (rc)
445 			return rc;
446 	}
447 	if (MACHINE_IS_LPAR) {
448 		rc = diag224_get_name_table();
449 		if (rc) {
450 			pr_err("The hardware system does not provide all "
451 			       "functions required by hypfs\n");
452 			debugfs_remove(dbfs_d204_file);
453 			return rc;
454 		}
455 	}
456 	return 0;
457 }
458 
459 void hypfs_diag_exit(void)
460 {
461 	debugfs_remove(dbfs_d204_file);
462 	diag224_delete_name_table();
463 	diag204_free_buffer();
464 	hypfs_dbfs_remove_file(&dbfs_file_d204);
465 }
466 
467 /*
468  * Functions to create the directory structure
469  * *******************************************
470  */
471 
472 static int hypfs_create_cpu_files(struct dentry *cpus_dir, void *cpu_info)
473 {
474 	struct dentry *cpu_dir;
475 	char buffer[TMP_SIZE];
476 	void *rc;
477 
478 	snprintf(buffer, TMP_SIZE, "%d", cpu_info__cpu_addr(diag204_info_type,
479 							    cpu_info));
480 	cpu_dir = hypfs_mkdir(cpus_dir, buffer);
481 	rc = hypfs_create_u64(cpu_dir, "mgmtime",
482 			      cpu_info__acc_time(diag204_info_type, cpu_info) -
483 			      cpu_info__lp_time(diag204_info_type, cpu_info));
484 	if (IS_ERR(rc))
485 		return PTR_ERR(rc);
486 	rc = hypfs_create_u64(cpu_dir, "cputime",
487 			      cpu_info__lp_time(diag204_info_type, cpu_info));
488 	if (IS_ERR(rc))
489 		return PTR_ERR(rc);
490 	if (diag204_info_type == DIAG204_INFO_EXT) {
491 		rc = hypfs_create_u64(cpu_dir, "onlinetime",
492 				      cpu_info__online_time(diag204_info_type,
493 							    cpu_info));
494 		if (IS_ERR(rc))
495 			return PTR_ERR(rc);
496 	}
497 	diag224_idx2name(cpu_info__ctidx(diag204_info_type, cpu_info), buffer);
498 	rc = hypfs_create_str(cpu_dir, "type", buffer);
499 	return PTR_RET(rc);
500 }
501 
502 static void *hypfs_create_lpar_files(struct dentry *systems_dir, void *part_hdr)
503 {
504 	struct dentry *cpus_dir;
505 	struct dentry *lpar_dir;
506 	char lpar_name[DIAG204_LPAR_NAME_LEN + 1];
507 	void *cpu_info;
508 	int i;
509 
510 	part_hdr__part_name(diag204_info_type, part_hdr, lpar_name);
511 	lpar_name[DIAG204_LPAR_NAME_LEN] = 0;
512 	lpar_dir = hypfs_mkdir(systems_dir, lpar_name);
513 	if (IS_ERR(lpar_dir))
514 		return lpar_dir;
515 	cpus_dir = hypfs_mkdir(lpar_dir, "cpus");
516 	if (IS_ERR(cpus_dir))
517 		return cpus_dir;
518 	cpu_info = part_hdr + part_hdr__size(diag204_info_type);
519 	for (i = 0; i < part_hdr__rcpus(diag204_info_type, part_hdr); i++) {
520 		int rc;
521 		rc = hypfs_create_cpu_files(cpus_dir, cpu_info);
522 		if (rc)
523 			return ERR_PTR(rc);
524 		cpu_info += cpu_info__size(diag204_info_type);
525 	}
526 	return cpu_info;
527 }
528 
529 static int hypfs_create_phys_cpu_files(struct dentry *cpus_dir, void *cpu_info)
530 {
531 	struct dentry *cpu_dir;
532 	char buffer[TMP_SIZE];
533 	void *rc;
534 
535 	snprintf(buffer, TMP_SIZE, "%i", phys_cpu__cpu_addr(diag204_info_type,
536 							    cpu_info));
537 	cpu_dir = hypfs_mkdir(cpus_dir, buffer);
538 	if (IS_ERR(cpu_dir))
539 		return PTR_ERR(cpu_dir);
540 	rc = hypfs_create_u64(cpu_dir, "mgmtime",
541 			      phys_cpu__mgm_time(diag204_info_type, cpu_info));
542 	if (IS_ERR(rc))
543 		return PTR_ERR(rc);
544 	diag224_idx2name(phys_cpu__ctidx(diag204_info_type, cpu_info), buffer);
545 	rc = hypfs_create_str(cpu_dir, "type", buffer);
546 	return PTR_RET(rc);
547 }
548 
549 static void *hypfs_create_phys_files(struct dentry *parent_dir, void *phys_hdr)
550 {
551 	int i;
552 	void *cpu_info;
553 	struct dentry *cpus_dir;
554 
555 	cpus_dir = hypfs_mkdir(parent_dir, "cpus");
556 	if (IS_ERR(cpus_dir))
557 		return cpus_dir;
558 	cpu_info = phys_hdr + phys_hdr__size(diag204_info_type);
559 	for (i = 0; i < phys_hdr__cpus(diag204_info_type, phys_hdr); i++) {
560 		int rc;
561 		rc = hypfs_create_phys_cpu_files(cpus_dir, cpu_info);
562 		if (rc)
563 			return ERR_PTR(rc);
564 		cpu_info += phys_cpu__size(diag204_info_type);
565 	}
566 	return cpu_info;
567 }
568 
569 int hypfs_diag_create_files(struct dentry *root)
570 {
571 	struct dentry *systems_dir, *hyp_dir;
572 	void *time_hdr, *part_hdr;
573 	int i, rc;
574 	void *buffer, *ptr;
575 
576 	buffer = diag204_store();
577 	if (IS_ERR(buffer))
578 		return PTR_ERR(buffer);
579 
580 	systems_dir = hypfs_mkdir(root, "systems");
581 	if (IS_ERR(systems_dir)) {
582 		rc = PTR_ERR(systems_dir);
583 		goto err_out;
584 	}
585 	time_hdr = (struct x_info_blk_hdr *)buffer;
586 	part_hdr = time_hdr + info_blk_hdr__size(diag204_info_type);
587 	for (i = 0; i < info_blk_hdr__npar(diag204_info_type, time_hdr); i++) {
588 		part_hdr = hypfs_create_lpar_files(systems_dir, part_hdr);
589 		if (IS_ERR(part_hdr)) {
590 			rc = PTR_ERR(part_hdr);
591 			goto err_out;
592 		}
593 	}
594 	if (info_blk_hdr__flags(diag204_info_type, time_hdr) &
595 	    DIAG204_LPAR_PHYS_FLG) {
596 		ptr = hypfs_create_phys_files(root, part_hdr);
597 		if (IS_ERR(ptr)) {
598 			rc = PTR_ERR(ptr);
599 			goto err_out;
600 		}
601 	}
602 	hyp_dir = hypfs_mkdir(root, "hyp");
603 	if (IS_ERR(hyp_dir)) {
604 		rc = PTR_ERR(hyp_dir);
605 		goto err_out;
606 	}
607 	ptr = hypfs_create_str(hyp_dir, "type", "LPAR Hypervisor");
608 	if (IS_ERR(ptr)) {
609 		rc = PTR_ERR(ptr);
610 		goto err_out;
611 	}
612 	rc = 0;
613 
614 err_out:
615 	return rc;
616 }
617