ARM: at91: fix board-rm9200-dt after sys_timer conversion
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / firmware / dmi_scan.c
1 #include <linux/types.h>
2 #include <linux/string.h>
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include <linux/ctype.h>
6 #include <linux/dmi.h>
7 #include <linux/efi.h>
8 #include <linux/bootmem.h>
9 #include <linux/random.h>
10 #include <asm/dmi.h>
11
12 /*
13 * DMI stands for "Desktop Management Interface". It is part
14 * of and an antecedent to, SMBIOS, which stands for System
15 * Management BIOS. See further: http://www.dmtf.org/standards
16 */
17 static char dmi_empty_string[] = " ";
18
19 static u16 __initdata dmi_ver;
20 /*
21 * Catch too early calls to dmi_check_system():
22 */
23 static int dmi_initialized;
24
25 static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
26 {
27 const u8 *bp = ((u8 *) dm) + dm->length;
28
29 if (s) {
30 s--;
31 while (s > 0 && *bp) {
32 bp += strlen(bp) + 1;
33 s--;
34 }
35
36 if (*bp != 0) {
37 size_t len = strlen(bp)+1;
38 size_t cmp_len = len > 8 ? 8 : len;
39
40 if (!memcmp(bp, dmi_empty_string, cmp_len))
41 return dmi_empty_string;
42 return bp;
43 }
44 }
45
46 return "";
47 }
48
49 static char * __init dmi_string(const struct dmi_header *dm, u8 s)
50 {
51 const char *bp = dmi_string_nosave(dm, s);
52 char *str;
53 size_t len;
54
55 if (bp == dmi_empty_string)
56 return dmi_empty_string;
57
58 len = strlen(bp) + 1;
59 str = dmi_alloc(len);
60 if (str != NULL)
61 strcpy(str, bp);
62 else
63 printk(KERN_ERR "dmi_string: cannot allocate %Zu bytes.\n", len);
64
65 return str;
66 }
67
68 /*
69 * We have to be cautious here. We have seen BIOSes with DMI pointers
70 * pointing to completely the wrong place for example
71 */
72 static void dmi_table(u8 *buf, int len, int num,
73 void (*decode)(const struct dmi_header *, void *),
74 void *private_data)
75 {
76 u8 *data = buf;
77 int i = 0;
78
79 /*
80 * Stop when we see all the items the table claimed to have
81 * OR we run off the end of the table (also happens)
82 */
83 while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
84 const struct dmi_header *dm = (const struct dmi_header *)data;
85
86 /*
87 * We want to know the total length (formatted area and
88 * strings) before decoding to make sure we won't run off the
89 * table in dmi_decode or dmi_string
90 */
91 data += dm->length;
92 while ((data - buf < len - 1) && (data[0] || data[1]))
93 data++;
94 if (data - buf < len - 1)
95 decode(dm, private_data);
96 data += 2;
97 i++;
98 }
99 }
100
101 static u32 dmi_base;
102 static u16 dmi_len;
103 static u16 dmi_num;
104
105 static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
106 void *))
107 {
108 u8 *buf;
109
110 buf = dmi_ioremap(dmi_base, dmi_len);
111 if (buf == NULL)
112 return -1;
113
114 dmi_table(buf, dmi_len, dmi_num, decode, NULL);
115
116 add_device_randomness(buf, dmi_len);
117
118 dmi_iounmap(buf, dmi_len);
119 return 0;
120 }
121
122 static int __init dmi_checksum(const u8 *buf, u8 len)
123 {
124 u8 sum = 0;
125 int a;
126
127 for (a = 0; a < len; a++)
128 sum += buf[a];
129
130 return sum == 0;
131 }
132
133 static char *dmi_ident[DMI_STRING_MAX];
134 static LIST_HEAD(dmi_devices);
135 int dmi_available;
136
137 /*
138 * Save a DMI string
139 */
140 static void __init dmi_save_ident(const struct dmi_header *dm, int slot, int string)
141 {
142 const char *d = (const char*) dm;
143 char *p;
144
145 if (dmi_ident[slot])
146 return;
147
148 p = dmi_string(dm, d[string]);
149 if (p == NULL)
150 return;
151
152 dmi_ident[slot] = p;
153 }
154
155 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int index)
156 {
157 const u8 *d = (u8*) dm + index;
158 char *s;
159 int is_ff = 1, is_00 = 1, i;
160
161 if (dmi_ident[slot])
162 return;
163
164 for (i = 0; i < 16 && (is_ff || is_00); i++) {
165 if (d[i] != 0x00)
166 is_00 = 0;
167 if (d[i] != 0xFF)
168 is_ff = 0;
169 }
170
171 if (is_ff || is_00)
172 return;
173
174 s = dmi_alloc(16*2+4+1);
175 if (!s)
176 return;
177
178 /*
179 * As of version 2.6 of the SMBIOS specification, the first 3 fields of
180 * the UUID are supposed to be little-endian encoded. The specification
181 * says that this is the defacto standard.
182 */
183 if (dmi_ver >= 0x0206)
184 sprintf(s, "%pUL", d);
185 else
186 sprintf(s, "%pUB", d);
187
188 dmi_ident[slot] = s;
189 }
190
191 static void __init dmi_save_type(const struct dmi_header *dm, int slot, int index)
192 {
193 const u8 *d = (u8*) dm + index;
194 char *s;
195
196 if (dmi_ident[slot])
197 return;
198
199 s = dmi_alloc(4);
200 if (!s)
201 return;
202
203 sprintf(s, "%u", *d & 0x7F);
204 dmi_ident[slot] = s;
205 }
206
207 static void __init dmi_save_one_device(int type, const char *name)
208 {
209 struct dmi_device *dev;
210
211 /* No duplicate device */
212 if (dmi_find_device(type, name, NULL))
213 return;
214
215 dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
216 if (!dev) {
217 printk(KERN_ERR "dmi_save_one_device: out of memory.\n");
218 return;
219 }
220
221 dev->type = type;
222 strcpy((char *)(dev + 1), name);
223 dev->name = (char *)(dev + 1);
224 dev->device_data = NULL;
225 list_add(&dev->list, &dmi_devices);
226 }
227
228 static void __init dmi_save_devices(const struct dmi_header *dm)
229 {
230 int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
231
232 for (i = 0; i < count; i++) {
233 const char *d = (char *)(dm + 1) + (i * 2);
234
235 /* Skip disabled device */
236 if ((*d & 0x80) == 0)
237 continue;
238
239 dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
240 }
241 }
242
243 static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
244 {
245 int i, count = *(u8 *)(dm + 1);
246 struct dmi_device *dev;
247
248 for (i = 1; i <= count; i++) {
249 char *devname = dmi_string(dm, i);
250
251 if (devname == dmi_empty_string)
252 continue;
253
254 dev = dmi_alloc(sizeof(*dev));
255 if (!dev) {
256 printk(KERN_ERR
257 "dmi_save_oem_strings_devices: out of memory.\n");
258 break;
259 }
260
261 dev->type = DMI_DEV_TYPE_OEM_STRING;
262 dev->name = devname;
263 dev->device_data = NULL;
264
265 list_add(&dev->list, &dmi_devices);
266 }
267 }
268
269 static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
270 {
271 struct dmi_device *dev;
272 void * data;
273
274 data = dmi_alloc(dm->length);
275 if (data == NULL) {
276 printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
277 return;
278 }
279
280 memcpy(data, dm, dm->length);
281
282 dev = dmi_alloc(sizeof(*dev));
283 if (!dev) {
284 printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
285 return;
286 }
287
288 dev->type = DMI_DEV_TYPE_IPMI;
289 dev->name = "IPMI controller";
290 dev->device_data = data;
291
292 list_add_tail(&dev->list, &dmi_devices);
293 }
294
295 static void __init dmi_save_dev_onboard(int instance, int segment, int bus,
296 int devfn, const char *name)
297 {
298 struct dmi_dev_onboard *onboard_dev;
299
300 onboard_dev = dmi_alloc(sizeof(*onboard_dev) + strlen(name) + 1);
301 if (!onboard_dev) {
302 printk(KERN_ERR "dmi_save_dev_onboard: out of memory.\n");
303 return;
304 }
305 onboard_dev->instance = instance;
306 onboard_dev->segment = segment;
307 onboard_dev->bus = bus;
308 onboard_dev->devfn = devfn;
309
310 strcpy((char *)&onboard_dev[1], name);
311 onboard_dev->dev.type = DMI_DEV_TYPE_DEV_ONBOARD;
312 onboard_dev->dev.name = (char *)&onboard_dev[1];
313 onboard_dev->dev.device_data = onboard_dev;
314
315 list_add(&onboard_dev->dev.list, &dmi_devices);
316 }
317
318 static void __init dmi_save_extended_devices(const struct dmi_header *dm)
319 {
320 const u8 *d = (u8*) dm + 5;
321
322 /* Skip disabled device */
323 if ((*d & 0x80) == 0)
324 return;
325
326 dmi_save_dev_onboard(*(d+1), *(u16 *)(d+2), *(d+4), *(d+5),
327 dmi_string_nosave(dm, *(d-1)));
328 dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d - 1)));
329 }
330
331 /*
332 * Process a DMI table entry. Right now all we care about are the BIOS
333 * and machine entries. For 2.5 we should pull the smbus controller info
334 * out of here.
335 */
336 static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
337 {
338 switch(dm->type) {
339 case 0: /* BIOS Information */
340 dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
341 dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
342 dmi_save_ident(dm, DMI_BIOS_DATE, 8);
343 break;
344 case 1: /* System Information */
345 dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
346 dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
347 dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
348 dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
349 dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
350 break;
351 case 2: /* Base Board Information */
352 dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
353 dmi_save_ident(dm, DMI_BOARD_NAME, 5);
354 dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
355 dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
356 dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
357 break;
358 case 3: /* Chassis Information */
359 dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
360 dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
361 dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
362 dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
363 dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
364 break;
365 case 10: /* Onboard Devices Information */
366 dmi_save_devices(dm);
367 break;
368 case 11: /* OEM Strings */
369 dmi_save_oem_strings_devices(dm);
370 break;
371 case 38: /* IPMI Device Information */
372 dmi_save_ipmi_device(dm);
373 break;
374 case 41: /* Onboard Devices Extended Information */
375 dmi_save_extended_devices(dm);
376 }
377 }
378
379 static void __init print_filtered(const char *info)
380 {
381 const char *p;
382
383 if (!info)
384 return;
385
386 for (p = info; *p; p++)
387 if (isprint(*p))
388 printk(KERN_CONT "%c", *p);
389 else
390 printk(KERN_CONT "\\x%02x", *p & 0xff);
391 }
392
393 static void __init dmi_dump_ids(void)
394 {
395 const char *board; /* Board Name is optional */
396
397 printk(KERN_DEBUG "DMI: ");
398 print_filtered(dmi_get_system_info(DMI_SYS_VENDOR));
399 printk(KERN_CONT " ");
400 print_filtered(dmi_get_system_info(DMI_PRODUCT_NAME));
401 board = dmi_get_system_info(DMI_BOARD_NAME);
402 if (board) {
403 printk(KERN_CONT "/");
404 print_filtered(board);
405 }
406 printk(KERN_CONT ", BIOS ");
407 print_filtered(dmi_get_system_info(DMI_BIOS_VERSION));
408 printk(KERN_CONT " ");
409 print_filtered(dmi_get_system_info(DMI_BIOS_DATE));
410 printk(KERN_CONT "\n");
411 }
412
413 static int __init dmi_present(const char __iomem *p)
414 {
415 u8 buf[15];
416
417 memcpy_fromio(buf, p, 15);
418 if (dmi_checksum(buf, 15)) {
419 dmi_num = (buf[13] << 8) | buf[12];
420 dmi_len = (buf[7] << 8) | buf[6];
421 dmi_base = (buf[11] << 24) | (buf[10] << 16) |
422 (buf[9] << 8) | buf[8];
423
424 if (dmi_walk_early(dmi_decode) == 0) {
425 if (dmi_ver)
426 pr_info("SMBIOS %d.%d present.\n",
427 dmi_ver >> 8, dmi_ver & 0xFF);
428 else {
429 dmi_ver = (buf[14] & 0xF0) << 4 |
430 (buf[14] & 0x0F);
431 pr_info("Legacy DMI %d.%d present.\n",
432 dmi_ver >> 8, dmi_ver & 0xFF);
433 }
434 dmi_dump_ids();
435 return 0;
436 }
437 }
438 dmi_ver = 0;
439 return 1;
440 }
441
442 static int __init smbios_present(const char __iomem *p)
443 {
444 u8 buf[32];
445 int offset = 0;
446
447 memcpy_fromio(buf, p, 32);
448 if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) {
449 dmi_ver = (buf[6] << 8) + buf[7];
450
451 /* Some BIOS report weird SMBIOS version, fix that up */
452 switch (dmi_ver) {
453 case 0x021F:
454 case 0x0221:
455 pr_debug("SMBIOS version fixup(2.%d->2.%d)\n",
456 dmi_ver & 0xFF, 3);
457 dmi_ver = 0x0203;
458 break;
459 case 0x0233:
460 pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6);
461 dmi_ver = 0x0206;
462 break;
463 }
464 offset = 16;
465 }
466 return dmi_present(buf + offset);
467 }
468
469 void __init dmi_scan_machine(void)
470 {
471 char __iomem *p, *q;
472 int rc;
473
474 if (efi_enabled) {
475 if (efi.smbios == EFI_INVALID_TABLE_ADDR)
476 goto error;
477
478 /* This is called as a core_initcall() because it isn't
479 * needed during early boot. This also means we can
480 * iounmap the space when we're done with it.
481 */
482 p = dmi_ioremap(efi.smbios, 32);
483 if (p == NULL)
484 goto error;
485
486 rc = smbios_present(p);
487 dmi_iounmap(p, 32);
488 if (!rc) {
489 dmi_available = 1;
490 goto out;
491 }
492 }
493 else {
494 /*
495 * no iounmap() for that ioremap(); it would be a no-op, but
496 * it's so early in setup that sucker gets confused into doing
497 * what it shouldn't if we actually call it.
498 */
499 p = dmi_ioremap(0xF0000, 0x10000);
500 if (p == NULL)
501 goto error;
502
503 for (q = p; q < p + 0x10000; q += 16) {
504 if (memcmp(q, "_SM_", 4) == 0 && q - p <= 0xFFE0)
505 rc = smbios_present(q);
506 else if (memcmp(q, "_DMI_", 5) == 0)
507 rc = dmi_present(q);
508 else
509 continue;
510 if (!rc) {
511 dmi_available = 1;
512 dmi_iounmap(p, 0x10000);
513 goto out;
514 }
515 }
516 dmi_iounmap(p, 0x10000);
517 }
518 error:
519 printk(KERN_INFO "DMI not present or invalid.\n");
520 out:
521 dmi_initialized = 1;
522 }
523
524 /**
525 * dmi_matches - check if dmi_system_id structure matches system DMI data
526 * @dmi: pointer to the dmi_system_id structure to check
527 */
528 static bool dmi_matches(const struct dmi_system_id *dmi)
529 {
530 int i;
531
532 WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n");
533
534 for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
535 int s = dmi->matches[i].slot;
536 if (s == DMI_NONE)
537 break;
538 if (dmi_ident[s]
539 && strstr(dmi_ident[s], dmi->matches[i].substr))
540 continue;
541 /* No match */
542 return false;
543 }
544 return true;
545 }
546
547 /**
548 * dmi_is_end_of_table - check for end-of-table marker
549 * @dmi: pointer to the dmi_system_id structure to check
550 */
551 static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
552 {
553 return dmi->matches[0].slot == DMI_NONE;
554 }
555
556 /**
557 * dmi_check_system - check system DMI data
558 * @list: array of dmi_system_id structures to match against
559 * All non-null elements of the list must match
560 * their slot's (field index's) data (i.e., each
561 * list string must be a substring of the specified
562 * DMI slot's string data) to be considered a
563 * successful match.
564 *
565 * Walk the blacklist table running matching functions until someone
566 * returns non zero or we hit the end. Callback function is called for
567 * each successful match. Returns the number of matches.
568 */
569 int dmi_check_system(const struct dmi_system_id *list)
570 {
571 int count = 0;
572 const struct dmi_system_id *d;
573
574 for (d = list; !dmi_is_end_of_table(d); d++)
575 if (dmi_matches(d)) {
576 count++;
577 if (d->callback && d->callback(d))
578 break;
579 }
580
581 return count;
582 }
583 EXPORT_SYMBOL(dmi_check_system);
584
585 /**
586 * dmi_first_match - find dmi_system_id structure matching system DMI data
587 * @list: array of dmi_system_id structures to match against
588 * All non-null elements of the list must match
589 * their slot's (field index's) data (i.e., each
590 * list string must be a substring of the specified
591 * DMI slot's string data) to be considered a
592 * successful match.
593 *
594 * Walk the blacklist table until the first match is found. Return the
595 * pointer to the matching entry or NULL if there's no match.
596 */
597 const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
598 {
599 const struct dmi_system_id *d;
600
601 for (d = list; !dmi_is_end_of_table(d); d++)
602 if (dmi_matches(d))
603 return d;
604
605 return NULL;
606 }
607 EXPORT_SYMBOL(dmi_first_match);
608
609 /**
610 * dmi_get_system_info - return DMI data value
611 * @field: data index (see enum dmi_field)
612 *
613 * Returns one DMI data value, can be used to perform
614 * complex DMI data checks.
615 */
616 const char *dmi_get_system_info(int field)
617 {
618 return dmi_ident[field];
619 }
620 EXPORT_SYMBOL(dmi_get_system_info);
621
622 /**
623 * dmi_name_in_serial - Check if string is in the DMI product serial information
624 * @str: string to check for
625 */
626 int dmi_name_in_serial(const char *str)
627 {
628 int f = DMI_PRODUCT_SERIAL;
629 if (dmi_ident[f] && strstr(dmi_ident[f], str))
630 return 1;
631 return 0;
632 }
633
634 /**
635 * dmi_name_in_vendors - Check if string is in the DMI system or board vendor name
636 * @str: Case sensitive Name
637 */
638 int dmi_name_in_vendors(const char *str)
639 {
640 static int fields[] = { DMI_SYS_VENDOR, DMI_BOARD_VENDOR, DMI_NONE };
641 int i;
642 for (i = 0; fields[i] != DMI_NONE; i++) {
643 int f = fields[i];
644 if (dmi_ident[f] && strstr(dmi_ident[f], str))
645 return 1;
646 }
647 return 0;
648 }
649 EXPORT_SYMBOL(dmi_name_in_vendors);
650
651 /**
652 * dmi_find_device - find onboard device by type/name
653 * @type: device type or %DMI_DEV_TYPE_ANY to match all device types
654 * @name: device name string or %NULL to match all
655 * @from: previous device found in search, or %NULL for new search.
656 *
657 * Iterates through the list of known onboard devices. If a device is
658 * found with a matching @vendor and @device, a pointer to its device
659 * structure is returned. Otherwise, %NULL is returned.
660 * A new search is initiated by passing %NULL as the @from argument.
661 * If @from is not %NULL, searches continue from next device.
662 */
663 const struct dmi_device * dmi_find_device(int type, const char *name,
664 const struct dmi_device *from)
665 {
666 const struct list_head *head = from ? &from->list : &dmi_devices;
667 struct list_head *d;
668
669 for(d = head->next; d != &dmi_devices; d = d->next) {
670 const struct dmi_device *dev =
671 list_entry(d, struct dmi_device, list);
672
673 if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
674 ((name == NULL) || (strcmp(dev->name, name) == 0)))
675 return dev;
676 }
677
678 return NULL;
679 }
680 EXPORT_SYMBOL(dmi_find_device);
681
682 /**
683 * dmi_get_date - parse a DMI date
684 * @field: data index (see enum dmi_field)
685 * @yearp: optional out parameter for the year
686 * @monthp: optional out parameter for the month
687 * @dayp: optional out parameter for the day
688 *
689 * The date field is assumed to be in the form resembling
690 * [mm[/dd]]/yy[yy] and the result is stored in the out
691 * parameters any or all of which can be omitted.
692 *
693 * If the field doesn't exist, all out parameters are set to zero
694 * and false is returned. Otherwise, true is returned with any
695 * invalid part of date set to zero.
696 *
697 * On return, year, month and day are guaranteed to be in the
698 * range of [0,9999], [0,12] and [0,31] respectively.
699 */
700 bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
701 {
702 int year = 0, month = 0, day = 0;
703 bool exists;
704 const char *s, *y;
705 char *e;
706
707 s = dmi_get_system_info(field);
708 exists = s;
709 if (!exists)
710 goto out;
711
712 /*
713 * Determine year first. We assume the date string resembles
714 * mm/dd/yy[yy] but the original code extracted only the year
715 * from the end. Keep the behavior in the spirit of no
716 * surprises.
717 */
718 y = strrchr(s, '/');
719 if (!y)
720 goto out;
721
722 y++;
723 year = simple_strtoul(y, &e, 10);
724 if (y != e && year < 100) { /* 2-digit year */
725 year += 1900;
726 if (year < 1996) /* no dates < spec 1.0 */
727 year += 100;
728 }
729 if (year > 9999) /* year should fit in %04d */
730 year = 0;
731
732 /* parse the mm and dd */
733 month = simple_strtoul(s, &e, 10);
734 if (s == e || *e != '/' || !month || month > 12) {
735 month = 0;
736 goto out;
737 }
738
739 s = e + 1;
740 day = simple_strtoul(s, &e, 10);
741 if (s == y || s == e || *e != '/' || day > 31)
742 day = 0;
743 out:
744 if (yearp)
745 *yearp = year;
746 if (monthp)
747 *monthp = month;
748 if (dayp)
749 *dayp = day;
750 return exists;
751 }
752 EXPORT_SYMBOL(dmi_get_date);
753
754 /**
755 * dmi_walk - Walk the DMI table and get called back for every record
756 * @decode: Callback function
757 * @private_data: Private data to be passed to the callback function
758 *
759 * Returns -1 when the DMI table can't be reached, 0 on success.
760 */
761 int dmi_walk(void (*decode)(const struct dmi_header *, void *),
762 void *private_data)
763 {
764 u8 *buf;
765
766 if (!dmi_available)
767 return -1;
768
769 buf = ioremap(dmi_base, dmi_len);
770 if (buf == NULL)
771 return -1;
772
773 dmi_table(buf, dmi_len, dmi_num, decode, private_data);
774
775 iounmap(buf);
776 return 0;
777 }
778 EXPORT_SYMBOL_GPL(dmi_walk);
779
780 /**
781 * dmi_match - compare a string to the dmi field (if exists)
782 * @f: DMI field identifier
783 * @str: string to compare the DMI field to
784 *
785 * Returns true if the requested field equals to the str (including NULL).
786 */
787 bool dmi_match(enum dmi_field f, const char *str)
788 {
789 const char *info = dmi_get_system_info(f);
790
791 if (info == NULL || str == NULL)
792 return info == str;
793
794 return !strcmp(info, str);
795 }
796 EXPORT_SYMBOL_GPL(dmi_match);