xref: /openbmc/linux/arch/s390/hypfs/hypfs_diag.c (revision 82ced6fd)
1 /*
2  *  arch/s390/hypfs/hypfs_diag.c
3  *    Hypervisor filesystem for Linux on s390. Diag 204 and 224
4  *    implementation.
5  *
6  *    Copyright IBM Corp. 2006, 2008
7  *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
8  */
9 
10 #define KMSG_COMPONENT "hypfs"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/types.h>
14 #include <linux/errno.h>
15 #include <linux/gfp.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include <linux/vmalloc.h>
19 #include <asm/ebcdic.h>
20 #include "hypfs.h"
21 
22 #define LPAR_NAME_LEN 8		/* lpar name len in diag 204 data */
23 #define CPU_NAME_LEN 16		/* type name len of cpus in diag224 name table */
24 #define TMP_SIZE 64		/* size of temporary buffers */
25 
26 /* diag 204 subcodes */
27 enum diag204_sc {
28 	SUBC_STIB4 = 4,
29 	SUBC_RSI = 5,
30 	SUBC_STIB6 = 6,
31 	SUBC_STIB7 = 7
32 };
33 
34 /* The two available diag 204 data formats */
35 enum diag204_format {
36 	INFO_SIMPLE = 0,
37 	INFO_EXT = 0x00010000
38 };
39 
40 /* bit is set in flags, when physical cpu info is included in diag 204 data */
41 #define LPAR_PHYS_FLG  0x80
42 
43 static char *diag224_cpu_names;			/* diag 224 name table */
44 static enum diag204_sc diag204_store_sc;	/* used subcode for store */
45 static enum diag204_format diag204_info_type;	/* used diag 204 data format */
46 
47 static void *diag204_buf;		/* 4K aligned buffer for diag204 data */
48 static void *diag204_buf_vmalloc;	/* vmalloc pointer for diag204 data */
49 static int diag204_buf_pages;		/* number of pages for diag204 data */
50 
51 /*
52  * DIAG 204 data structures and member access functions.
53  *
54  * Since we have two different diag 204 data formats for old and new s390
55  * machines, we do not access the structs directly, but use getter functions for
56  * each struct member instead. This should make the code more readable.
57  */
58 
59 /* Time information block */
60 
61 struct info_blk_hdr {
62 	__u8  npar;
63 	__u8  flags;
64 	__u16 tslice;
65 	__u16 phys_cpus;
66 	__u16 this_part;
67 	__u64 curtod;
68 } __attribute__ ((packed));
69 
70 struct x_info_blk_hdr {
71 	__u8  npar;
72 	__u8  flags;
73 	__u16 tslice;
74 	__u16 phys_cpus;
75 	__u16 this_part;
76 	__u64 curtod1;
77 	__u64 curtod2;
78 	char reserved[40];
79 } __attribute__ ((packed));
80 
81 static inline int info_blk_hdr__size(enum diag204_format type)
82 {
83 	if (type == INFO_SIMPLE)
84 		return sizeof(struct info_blk_hdr);
85 	else /* INFO_EXT */
86 		return sizeof(struct x_info_blk_hdr);
87 }
88 
89 static inline __u8 info_blk_hdr__npar(enum diag204_format type, void *hdr)
90 {
91 	if (type == INFO_SIMPLE)
92 		return ((struct info_blk_hdr *)hdr)->npar;
93 	else /* INFO_EXT */
94 		return ((struct x_info_blk_hdr *)hdr)->npar;
95 }
96 
97 static inline __u8 info_blk_hdr__flags(enum diag204_format type, void *hdr)
98 {
99 	if (type == INFO_SIMPLE)
100 		return ((struct info_blk_hdr *)hdr)->flags;
101 	else /* INFO_EXT */
102 		return ((struct x_info_blk_hdr *)hdr)->flags;
103 }
104 
105 static inline __u16 info_blk_hdr__pcpus(enum diag204_format type, void *hdr)
106 {
107 	if (type == INFO_SIMPLE)
108 		return ((struct info_blk_hdr *)hdr)->phys_cpus;
109 	else /* INFO_EXT */
110 		return ((struct x_info_blk_hdr *)hdr)->phys_cpus;
111 }
112 
113 /* Partition header */
114 
115 struct part_hdr {
116 	__u8 pn;
117 	__u8 cpus;
118 	char reserved[6];
119 	char part_name[LPAR_NAME_LEN];
120 } __attribute__ ((packed));
121 
122 struct x_part_hdr {
123 	__u8  pn;
124 	__u8  cpus;
125 	__u8  rcpus;
126 	__u8  pflag;
127 	__u32 mlu;
128 	char  part_name[LPAR_NAME_LEN];
129 	char  lpc_name[8];
130 	char  os_name[8];
131 	__u64 online_cs;
132 	__u64 online_es;
133 	__u8  upid;
134 	char  reserved1[3];
135 	__u32 group_mlu;
136 	char  group_name[8];
137 	char  reserved2[32];
138 } __attribute__ ((packed));
139 
140 static inline int part_hdr__size(enum diag204_format type)
141 {
142 	if (type == INFO_SIMPLE)
143 		return sizeof(struct part_hdr);
144 	else /* INFO_EXT */
145 		return sizeof(struct x_part_hdr);
146 }
147 
148 static inline __u8 part_hdr__rcpus(enum diag204_format type, void *hdr)
149 {
150 	if (type == INFO_SIMPLE)
151 		return ((struct part_hdr *)hdr)->cpus;
152 	else /* INFO_EXT */
153 		return ((struct x_part_hdr *)hdr)->rcpus;
154 }
155 
156 static inline void part_hdr__part_name(enum diag204_format type, void *hdr,
157 				       char *name)
158 {
159 	if (type == INFO_SIMPLE)
160 		memcpy(name, ((struct part_hdr *)hdr)->part_name,
161 		       LPAR_NAME_LEN);
162 	else /* INFO_EXT */
163 		memcpy(name, ((struct x_part_hdr *)hdr)->part_name,
164 		       LPAR_NAME_LEN);
165 	EBCASC(name, LPAR_NAME_LEN);
166 	name[LPAR_NAME_LEN] = 0;
167 	strstrip(name);
168 }
169 
170 struct cpu_info {
171 	__u16 cpu_addr;
172 	char  reserved1[2];
173 	__u8  ctidx;
174 	__u8  cflag;
175 	__u16 weight;
176 	__u64 acc_time;
177 	__u64 lp_time;
178 } __attribute__ ((packed));
179 
180 struct x_cpu_info {
181 	__u16 cpu_addr;
182 	char  reserved1[2];
183 	__u8  ctidx;
184 	__u8  cflag;
185 	__u16 weight;
186 	__u64 acc_time;
187 	__u64 lp_time;
188 	__u16 min_weight;
189 	__u16 cur_weight;
190 	__u16 max_weight;
191 	char  reseved2[2];
192 	__u64 online_time;
193 	__u64 wait_time;
194 	__u32 pma_weight;
195 	__u32 polar_weight;
196 	char  reserved3[40];
197 } __attribute__ ((packed));
198 
199 /* CPU info block */
200 
201 static inline int cpu_info__size(enum diag204_format type)
202 {
203 	if (type == INFO_SIMPLE)
204 		return sizeof(struct cpu_info);
205 	else /* INFO_EXT */
206 		return sizeof(struct x_cpu_info);
207 }
208 
209 static inline __u8 cpu_info__ctidx(enum diag204_format type, void *hdr)
210 {
211 	if (type == INFO_SIMPLE)
212 		return ((struct cpu_info *)hdr)->ctidx;
213 	else /* INFO_EXT */
214 		return ((struct x_cpu_info *)hdr)->ctidx;
215 }
216 
217 static inline __u16 cpu_info__cpu_addr(enum diag204_format type, void *hdr)
218 {
219 	if (type == INFO_SIMPLE)
220 		return ((struct cpu_info *)hdr)->cpu_addr;
221 	else /* INFO_EXT */
222 		return ((struct x_cpu_info *)hdr)->cpu_addr;
223 }
224 
225 static inline __u64 cpu_info__acc_time(enum diag204_format type, void *hdr)
226 {
227 	if (type == INFO_SIMPLE)
228 		return ((struct cpu_info *)hdr)->acc_time;
229 	else /* INFO_EXT */
230 		return ((struct x_cpu_info *)hdr)->acc_time;
231 }
232 
233 static inline __u64 cpu_info__lp_time(enum diag204_format type, void *hdr)
234 {
235 	if (type == INFO_SIMPLE)
236 		return ((struct cpu_info *)hdr)->lp_time;
237 	else /* INFO_EXT */
238 		return ((struct x_cpu_info *)hdr)->lp_time;
239 }
240 
241 static inline __u64 cpu_info__online_time(enum diag204_format type, void *hdr)
242 {
243 	if (type == INFO_SIMPLE)
244 		return 0;	/* online_time not available in simple info */
245 	else /* INFO_EXT */
246 		return ((struct x_cpu_info *)hdr)->online_time;
247 }
248 
249 /* Physical header */
250 
251 struct phys_hdr {
252 	char reserved1[1];
253 	__u8 cpus;
254 	char reserved2[6];
255 	char mgm_name[8];
256 } __attribute__ ((packed));
257 
258 struct x_phys_hdr {
259 	char reserved1[1];
260 	__u8 cpus;
261 	char reserved2[6];
262 	char mgm_name[8];
263 	char reserved3[80];
264 } __attribute__ ((packed));
265 
266 static inline int phys_hdr__size(enum diag204_format type)
267 {
268 	if (type == INFO_SIMPLE)
269 		return sizeof(struct phys_hdr);
270 	else /* INFO_EXT */
271 		return sizeof(struct x_phys_hdr);
272 }
273 
274 static inline __u8 phys_hdr__cpus(enum diag204_format type, void *hdr)
275 {
276 	if (type == INFO_SIMPLE)
277 		return ((struct phys_hdr *)hdr)->cpus;
278 	else /* INFO_EXT */
279 		return ((struct x_phys_hdr *)hdr)->cpus;
280 }
281 
282 /* Physical CPU info block */
283 
284 struct phys_cpu {
285 	__u16 cpu_addr;
286 	char  reserved1[2];
287 	__u8  ctidx;
288 	char  reserved2[3];
289 	__u64 mgm_time;
290 	char  reserved3[8];
291 } __attribute__ ((packed));
292 
293 struct x_phys_cpu {
294 	__u16 cpu_addr;
295 	char  reserved1[2];
296 	__u8  ctidx;
297 	char  reserved2[3];
298 	__u64 mgm_time;
299 	char  reserved3[80];
300 } __attribute__ ((packed));
301 
302 static inline int phys_cpu__size(enum diag204_format type)
303 {
304 	if (type == INFO_SIMPLE)
305 		return sizeof(struct phys_cpu);
306 	else /* INFO_EXT */
307 		return sizeof(struct x_phys_cpu);
308 }
309 
310 static inline __u16 phys_cpu__cpu_addr(enum diag204_format type, void *hdr)
311 {
312 	if (type == INFO_SIMPLE)
313 		return ((struct phys_cpu *)hdr)->cpu_addr;
314 	else /* INFO_EXT */
315 		return ((struct x_phys_cpu *)hdr)->cpu_addr;
316 }
317 
318 static inline __u64 phys_cpu__mgm_time(enum diag204_format type, void *hdr)
319 {
320 	if (type == INFO_SIMPLE)
321 		return ((struct phys_cpu *)hdr)->mgm_time;
322 	else /* INFO_EXT */
323 		return ((struct x_phys_cpu *)hdr)->mgm_time;
324 }
325 
326 static inline __u64 phys_cpu__ctidx(enum diag204_format type, void *hdr)
327 {
328 	if (type == INFO_SIMPLE)
329 		return ((struct phys_cpu *)hdr)->ctidx;
330 	else /* INFO_EXT */
331 		return ((struct x_phys_cpu *)hdr)->ctidx;
332 }
333 
334 /* Diagnose 204 functions */
335 
336 static int diag204(unsigned long subcode, unsigned long size, void *addr)
337 {
338 	register unsigned long _subcode asm("0") = subcode;
339 	register unsigned long _size asm("1") = size;
340 
341 	asm volatile(
342 		"	diag	%2,%0,0x204\n"
343 		"0:\n"
344 		EX_TABLE(0b,0b)
345 		: "+d" (_subcode), "+d" (_size) : "d" (addr) : "memory");
346 	if (_subcode)
347 		return -1;
348 	return _size;
349 }
350 
351 /*
352  * For the old diag subcode 4 with simple data format we have to use real
353  * memory. If we use subcode 6 or 7 with extended data format, we can (and
354  * should) use vmalloc, since we need a lot of memory in that case. Currently
355  * up to 93 pages!
356  */
357 
358 static void diag204_free_buffer(void)
359 {
360 	if (!diag204_buf)
361 		return;
362 	if (diag204_buf_vmalloc) {
363 		vfree(diag204_buf_vmalloc);
364 		diag204_buf_vmalloc = NULL;
365 	} else {
366 		free_pages((unsigned long) diag204_buf, 0);
367 	}
368 	diag204_buf_pages = 0;
369 	diag204_buf = NULL;
370 }
371 
372 static void *diag204_alloc_vbuf(int pages)
373 {
374 	/* The buffer has to be page aligned! */
375 	diag204_buf_vmalloc = vmalloc(PAGE_SIZE * (pages + 1));
376 	if (!diag204_buf_vmalloc)
377 		return ERR_PTR(-ENOMEM);
378 	diag204_buf = (void*)((unsigned long)diag204_buf_vmalloc
379 				& ~0xfffUL) + 0x1000;
380 	diag204_buf_pages = pages;
381 	return diag204_buf;
382 }
383 
384 static void *diag204_alloc_rbuf(void)
385 {
386 	diag204_buf = (void*)__get_free_pages(GFP_KERNEL,0);
387 	if (!diag204_buf)
388 		return ERR_PTR(-ENOMEM);
389 	diag204_buf_pages = 1;
390 	return diag204_buf;
391 }
392 
393 static void *diag204_get_buffer(enum diag204_format fmt, int *pages)
394 {
395 	if (diag204_buf) {
396 		*pages = diag204_buf_pages;
397 		return diag204_buf;
398 	}
399 	if (fmt == INFO_SIMPLE) {
400 		*pages = 1;
401 		return diag204_alloc_rbuf();
402 	} else {/* INFO_EXT */
403 		*pages = diag204((unsigned long)SUBC_RSI |
404 				 (unsigned long)INFO_EXT, 0, NULL);
405 		if (*pages <= 0)
406 			return ERR_PTR(-ENOSYS);
407 		else
408 			return diag204_alloc_vbuf(*pages);
409 	}
410 }
411 
412 /*
413  * diag204_probe() has to find out, which type of diagnose 204 implementation
414  * we have on our machine. Currently there are three possible scanarios:
415  *   - subcode 4   + simple data format (only one page)
416  *   - subcode 4-6 + extended data format
417  *   - subcode 4-7 + extended data format
418  *
419  * Subcode 5 is used to retrieve the size of the data, provided by subcodes
420  * 6 and 7. Subcode 7 basically has the same function as subcode 6. In addition
421  * to subcode 6 it provides also information about secondary cpus.
422  * In order to get as much information as possible, we first try
423  * subcode 7, then 6 and if both fail, we use subcode 4.
424  */
425 
426 static int diag204_probe(void)
427 {
428 	void *buf;
429 	int pages, rc;
430 
431 	buf = diag204_get_buffer(INFO_EXT, &pages);
432 	if (!IS_ERR(buf)) {
433 		if (diag204((unsigned long)SUBC_STIB7 |
434 			    (unsigned long)INFO_EXT, pages, buf) >= 0) {
435 			diag204_store_sc = SUBC_STIB7;
436 			diag204_info_type = INFO_EXT;
437 			goto out;
438 		}
439 		if (diag204((unsigned long)SUBC_STIB6 |
440 			    (unsigned long)INFO_EXT, pages, buf) >= 0) {
441 			diag204_store_sc = SUBC_STIB7;
442 			diag204_info_type = INFO_EXT;
443 			goto out;
444 		}
445 		diag204_free_buffer();
446 	}
447 
448 	/* subcodes 6 and 7 failed, now try subcode 4 */
449 
450 	buf = diag204_get_buffer(INFO_SIMPLE, &pages);
451 	if (IS_ERR(buf)) {
452 		rc = PTR_ERR(buf);
453 		goto fail_alloc;
454 	}
455 	if (diag204((unsigned long)SUBC_STIB4 |
456 		    (unsigned long)INFO_SIMPLE, pages, buf) >= 0) {
457 		diag204_store_sc = SUBC_STIB4;
458 		diag204_info_type = INFO_SIMPLE;
459 		goto out;
460 	} else {
461 		rc = -ENOSYS;
462 		goto fail_store;
463 	}
464 out:
465 	rc = 0;
466 fail_store:
467 	diag204_free_buffer();
468 fail_alloc:
469 	return rc;
470 }
471 
472 static void *diag204_store(void)
473 {
474 	void *buf;
475 	int pages;
476 
477 	buf = diag204_get_buffer(diag204_info_type, &pages);
478 	if (IS_ERR(buf))
479 		goto out;
480 	if (diag204((unsigned long)diag204_store_sc |
481 		    (unsigned long)diag204_info_type, pages, buf) < 0)
482 		return ERR_PTR(-ENOSYS);
483 out:
484 	return buf;
485 }
486 
487 /* Diagnose 224 functions */
488 
489 static int diag224(void *ptr)
490 {
491 	int rc = -ENOTSUPP;
492 
493 	asm volatile(
494 		"	diag	%1,%2,0x224\n"
495 		"0:	lhi	%0,0x0\n"
496 		"1:\n"
497 		EX_TABLE(0b,1b)
498 		: "+d" (rc) :"d" (0), "d" (ptr) : "memory");
499 	return rc;
500 }
501 
502 static int diag224_get_name_table(void)
503 {
504 	/* memory must be below 2GB */
505 	diag224_cpu_names = kmalloc(PAGE_SIZE, GFP_KERNEL | GFP_DMA);
506 	if (!diag224_cpu_names)
507 		return -ENOMEM;
508 	if (diag224(diag224_cpu_names)) {
509 		kfree(diag224_cpu_names);
510 		return -ENOTSUPP;
511 	}
512 	EBCASC(diag224_cpu_names + 16, (*diag224_cpu_names + 1) * 16);
513 	return 0;
514 }
515 
516 static void diag224_delete_name_table(void)
517 {
518 	kfree(diag224_cpu_names);
519 }
520 
521 static int diag224_idx2name(int index, char *name)
522 {
523 	memcpy(name, diag224_cpu_names + ((index + 1) * CPU_NAME_LEN),
524 		CPU_NAME_LEN);
525 	name[CPU_NAME_LEN] = 0;
526 	strstrip(name);
527 	return 0;
528 }
529 
530 __init int hypfs_diag_init(void)
531 {
532 	int rc;
533 
534 	if (diag204_probe()) {
535 		pr_err("The hardware system does not support hypfs\n");
536 		return -ENODATA;
537 	}
538 	rc = diag224_get_name_table();
539 	if (rc) {
540 		diag204_free_buffer();
541 		pr_err("The hardware system does not provide all "
542 		       "functions required by hypfs\n");
543 	}
544 	return rc;
545 }
546 
547 void hypfs_diag_exit(void)
548 {
549 	diag224_delete_name_table();
550 	diag204_free_buffer();
551 }
552 
553 /*
554  * Functions to create the directory structure
555  * *******************************************
556  */
557 
558 static int hypfs_create_cpu_files(struct super_block *sb,
559 				  struct dentry *cpus_dir, void *cpu_info)
560 {
561 	struct dentry *cpu_dir;
562 	char buffer[TMP_SIZE];
563 	void *rc;
564 
565 	snprintf(buffer, TMP_SIZE, "%d", cpu_info__cpu_addr(diag204_info_type,
566 							    cpu_info));
567 	cpu_dir = hypfs_mkdir(sb, cpus_dir, buffer);
568 	rc = hypfs_create_u64(sb, cpu_dir, "mgmtime",
569 			      cpu_info__acc_time(diag204_info_type, cpu_info) -
570 			      cpu_info__lp_time(diag204_info_type, cpu_info));
571 	if (IS_ERR(rc))
572 		return PTR_ERR(rc);
573 	rc = hypfs_create_u64(sb, cpu_dir, "cputime",
574 			      cpu_info__lp_time(diag204_info_type, cpu_info));
575 	if (IS_ERR(rc))
576 		return PTR_ERR(rc);
577 	if (diag204_info_type == INFO_EXT) {
578 		rc = hypfs_create_u64(sb, cpu_dir, "onlinetime",
579 				      cpu_info__online_time(diag204_info_type,
580 							    cpu_info));
581 		if (IS_ERR(rc))
582 			return PTR_ERR(rc);
583 	}
584 	diag224_idx2name(cpu_info__ctidx(diag204_info_type, cpu_info), buffer);
585 	rc = hypfs_create_str(sb, cpu_dir, "type", buffer);
586 	if (IS_ERR(rc))
587 		return PTR_ERR(rc);
588 	return 0;
589 }
590 
591 static void *hypfs_create_lpar_files(struct super_block *sb,
592 				     struct dentry *systems_dir, void *part_hdr)
593 {
594 	struct dentry *cpus_dir;
595 	struct dentry *lpar_dir;
596 	char lpar_name[LPAR_NAME_LEN + 1];
597 	void *cpu_info;
598 	int i;
599 
600 	part_hdr__part_name(diag204_info_type, part_hdr, lpar_name);
601 	lpar_name[LPAR_NAME_LEN] = 0;
602 	lpar_dir = hypfs_mkdir(sb, systems_dir, lpar_name);
603 	if (IS_ERR(lpar_dir))
604 		return lpar_dir;
605 	cpus_dir = hypfs_mkdir(sb, lpar_dir, "cpus");
606 	if (IS_ERR(cpus_dir))
607 		return cpus_dir;
608 	cpu_info = part_hdr + part_hdr__size(diag204_info_type);
609 	for (i = 0; i < part_hdr__rcpus(diag204_info_type, part_hdr); i++) {
610 		int rc;
611 		rc = hypfs_create_cpu_files(sb, cpus_dir, cpu_info);
612 		if (rc)
613 			return ERR_PTR(rc);
614 		cpu_info += cpu_info__size(diag204_info_type);
615 	}
616 	return cpu_info;
617 }
618 
619 static int hypfs_create_phys_cpu_files(struct super_block *sb,
620 				       struct dentry *cpus_dir, void *cpu_info)
621 {
622 	struct dentry *cpu_dir;
623 	char buffer[TMP_SIZE];
624 	void *rc;
625 
626 	snprintf(buffer, TMP_SIZE, "%i", phys_cpu__cpu_addr(diag204_info_type,
627 							    cpu_info));
628 	cpu_dir = hypfs_mkdir(sb, cpus_dir, buffer);
629 	if (IS_ERR(cpu_dir))
630 		return PTR_ERR(cpu_dir);
631 	rc = hypfs_create_u64(sb, cpu_dir, "mgmtime",
632 			      phys_cpu__mgm_time(diag204_info_type, cpu_info));
633 	if (IS_ERR(rc))
634 		return PTR_ERR(rc);
635 	diag224_idx2name(phys_cpu__ctidx(diag204_info_type, cpu_info), buffer);
636 	rc = hypfs_create_str(sb, cpu_dir, "type", buffer);
637 	if (IS_ERR(rc))
638 		return PTR_ERR(rc);
639 	return 0;
640 }
641 
642 static void *hypfs_create_phys_files(struct super_block *sb,
643 				     struct dentry *parent_dir, void *phys_hdr)
644 {
645 	int i;
646 	void *cpu_info;
647 	struct dentry *cpus_dir;
648 
649 	cpus_dir = hypfs_mkdir(sb, parent_dir, "cpus");
650 	if (IS_ERR(cpus_dir))
651 		return cpus_dir;
652 	cpu_info = phys_hdr + phys_hdr__size(diag204_info_type);
653 	for (i = 0; i < phys_hdr__cpus(diag204_info_type, phys_hdr); i++) {
654 		int rc;
655 		rc = hypfs_create_phys_cpu_files(sb, cpus_dir, cpu_info);
656 		if (rc)
657 			return ERR_PTR(rc);
658 		cpu_info += phys_cpu__size(diag204_info_type);
659 	}
660 	return cpu_info;
661 }
662 
663 int hypfs_diag_create_files(struct super_block *sb, struct dentry *root)
664 {
665 	struct dentry *systems_dir, *hyp_dir;
666 	void *time_hdr, *part_hdr;
667 	int i, rc;
668 	void *buffer, *ptr;
669 
670 	buffer = diag204_store();
671 	if (IS_ERR(buffer))
672 		return PTR_ERR(buffer);
673 
674 	systems_dir = hypfs_mkdir(sb, root, "systems");
675 	if (IS_ERR(systems_dir)) {
676 		rc = PTR_ERR(systems_dir);
677 		goto err_out;
678 	}
679 	time_hdr = (struct x_info_blk_hdr *)buffer;
680 	part_hdr = time_hdr + info_blk_hdr__size(diag204_info_type);
681 	for (i = 0; i < info_blk_hdr__npar(diag204_info_type, time_hdr); i++) {
682 		part_hdr = hypfs_create_lpar_files(sb, systems_dir, part_hdr);
683 		if (IS_ERR(part_hdr)) {
684 			rc = PTR_ERR(part_hdr);
685 			goto err_out;
686 		}
687 	}
688 	if (info_blk_hdr__flags(diag204_info_type, time_hdr) & LPAR_PHYS_FLG) {
689 		ptr = hypfs_create_phys_files(sb, root, part_hdr);
690 		if (IS_ERR(ptr)) {
691 			rc = PTR_ERR(ptr);
692 			goto err_out;
693 		}
694 	}
695 	hyp_dir = hypfs_mkdir(sb, root, "hyp");
696 	if (IS_ERR(hyp_dir)) {
697 		rc = PTR_ERR(hyp_dir);
698 		goto err_out;
699 	}
700 	ptr = hypfs_create_str(sb, hyp_dir, "type", "LPAR Hypervisor");
701 	if (IS_ERR(ptr)) {
702 		rc = PTR_ERR(ptr);
703 		goto err_out;
704 	}
705 	rc = 0;
706 
707 err_out:
708 	return rc;
709 }
710