1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/string.h>
4 #include <linux/init.h>
5 #include <linux/module.h>
6 #include <linux/ctype.h>
7 #include <linux/dmi.h>
8 #include <linux/efi.h>
9 #include <linux/memblock.h>
10 #include <linux/random.h>
11 #include <asm/dmi.h>
12 #include <asm/unaligned.h>
13
14 #ifndef SMBIOS_ENTRY_POINT_SCAN_START
15 #define SMBIOS_ENTRY_POINT_SCAN_START 0xF0000
16 #endif
17
18 struct kobject *dmi_kobj;
19 EXPORT_SYMBOL_GPL(dmi_kobj);
20
21 /*
22 * DMI stands for "Desktop Management Interface". It is part
23 * of and an antecedent to, SMBIOS, which stands for System
24 * Management BIOS. See further: https://www.dmtf.org/standards
25 */
26 static const char dmi_empty_string[] = "";
27
28 static u32 dmi_ver __initdata;
29 static u32 dmi_len;
30 static u16 dmi_num;
31 static u8 smbios_entry_point[32];
32 static int smbios_entry_point_size;
33
34 /* DMI system identification string used during boot */
35 static char dmi_ids_string[128] __initdata;
36
37 static struct dmi_memdev_info {
38 const char *device;
39 const char *bank;
40 u64 size; /* bytes */
41 u16 handle;
42 u8 type; /* DDR2, DDR3, DDR4 etc */
43 } *dmi_memdev;
44 static int dmi_memdev_nr;
45
dmi_string_nosave(const struct dmi_header * dm,u8 s)46 static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
47 {
48 const u8 *bp = ((u8 *) dm) + dm->length;
49 const u8 *nsp;
50
51 if (s) {
52 while (--s > 0 && *bp)
53 bp += strlen(bp) + 1;
54
55 /* Strings containing only spaces are considered empty */
56 nsp = bp;
57 while (*nsp == ' ')
58 nsp++;
59 if (*nsp != '\0')
60 return bp;
61 }
62
63 return dmi_empty_string;
64 }
65
dmi_string(const struct dmi_header * dm,u8 s)66 static const char * __init dmi_string(const struct dmi_header *dm, u8 s)
67 {
68 const char *bp = dmi_string_nosave(dm, s);
69 char *str;
70 size_t len;
71
72 if (bp == dmi_empty_string)
73 return dmi_empty_string;
74
75 len = strlen(bp) + 1;
76 str = dmi_alloc(len);
77 if (str != NULL)
78 strcpy(str, bp);
79
80 return str;
81 }
82
83 /*
84 * We have to be cautious here. We have seen BIOSes with DMI pointers
85 * pointing to completely the wrong place for example
86 */
dmi_decode_table(u8 * buf,void (* decode)(const struct dmi_header *,void *),void * private_data)87 static void dmi_decode_table(u8 *buf,
88 void (*decode)(const struct dmi_header *, void *),
89 void *private_data)
90 {
91 u8 *data = buf;
92 int i = 0;
93
94 /*
95 * Stop when we have seen all the items the table claimed to have
96 * (SMBIOS < 3.0 only) OR we reach an end-of-table marker (SMBIOS
97 * >= 3.0 only) OR we run off the end of the table (should never
98 * happen but sometimes does on bogus implementations.)
99 */
100 while ((!dmi_num || i < dmi_num) &&
101 (data - buf + sizeof(struct dmi_header)) <= dmi_len) {
102 const struct dmi_header *dm = (const struct dmi_header *)data;
103
104 /*
105 * If a short entry is found (less than 4 bytes), not only it
106 * is invalid, but we cannot reliably locate the next entry.
107 */
108 if (dm->length < sizeof(struct dmi_header)) {
109 pr_warn(FW_BUG
110 "Corrupted DMI table, offset %zd (only %d entries processed)\n",
111 data - buf, i);
112 break;
113 }
114
115 /*
116 * We want to know the total length (formatted area and
117 * strings) before decoding to make sure we won't run off the
118 * table in dmi_decode or dmi_string
119 */
120 data += dm->length;
121 while ((data - buf < dmi_len - 1) && (data[0] || data[1]))
122 data++;
123 if (data - buf < dmi_len - 1)
124 decode(dm, private_data);
125
126 data += 2;
127 i++;
128
129 /*
130 * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
131 * For tables behind a 64-bit entry point, we have no item
132 * count and no exact table length, so stop on end-of-table
133 * marker. For tables behind a 32-bit entry point, we have
134 * seen OEM structures behind the end-of-table marker on
135 * some systems, so don't trust it.
136 */
137 if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE)
138 break;
139 }
140
141 /* Trim DMI table length if needed */
142 if (dmi_len > data - buf)
143 dmi_len = data - buf;
144 }
145
146 static phys_addr_t dmi_base;
147
dmi_walk_early(void (* decode)(const struct dmi_header *,void *))148 static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
149 void *))
150 {
151 u8 *buf;
152 u32 orig_dmi_len = dmi_len;
153
154 buf = dmi_early_remap(dmi_base, orig_dmi_len);
155 if (buf == NULL)
156 return -ENOMEM;
157
158 dmi_decode_table(buf, decode, NULL);
159
160 add_device_randomness(buf, dmi_len);
161
162 dmi_early_unmap(buf, orig_dmi_len);
163 return 0;
164 }
165
dmi_checksum(const u8 * buf,u8 len)166 static int __init dmi_checksum(const u8 *buf, u8 len)
167 {
168 u8 sum = 0;
169 int a;
170
171 for (a = 0; a < len; a++)
172 sum += buf[a];
173
174 return sum == 0;
175 }
176
177 static const char *dmi_ident[DMI_STRING_MAX];
178 static LIST_HEAD(dmi_devices);
179 int dmi_available;
180 EXPORT_SYMBOL_GPL(dmi_available);
181
182 /*
183 * Save a DMI string
184 */
dmi_save_ident(const struct dmi_header * dm,int slot,int string)185 static void __init dmi_save_ident(const struct dmi_header *dm, int slot,
186 int string)
187 {
188 const char *d = (const char *) dm;
189 const char *p;
190
191 if (dmi_ident[slot] || dm->length <= string)
192 return;
193
194 p = dmi_string(dm, d[string]);
195 if (p == NULL)
196 return;
197
198 dmi_ident[slot] = p;
199 }
200
dmi_save_release(const struct dmi_header * dm,int slot,int index)201 static void __init dmi_save_release(const struct dmi_header *dm, int slot,
202 int index)
203 {
204 const u8 *minor, *major;
205 char *s;
206
207 /* If the table doesn't have the field, let's return */
208 if (dmi_ident[slot] || dm->length < index)
209 return;
210
211 minor = (u8 *) dm + index;
212 major = (u8 *) dm + index - 1;
213
214 /* As per the spec, if the system doesn't support this field,
215 * the value is FF
216 */
217 if (*major == 0xFF && *minor == 0xFF)
218 return;
219
220 s = dmi_alloc(8);
221 if (!s)
222 return;
223
224 sprintf(s, "%u.%u", *major, *minor);
225
226 dmi_ident[slot] = s;
227 }
228
dmi_save_uuid(const struct dmi_header * dm,int slot,int index)229 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
230 int index)
231 {
232 const u8 *d;
233 char *s;
234 int is_ff = 1, is_00 = 1, i;
235
236 if (dmi_ident[slot] || dm->length < index + 16)
237 return;
238
239 d = (u8 *) dm + index;
240 for (i = 0; i < 16 && (is_ff || is_00); i++) {
241 if (d[i] != 0x00)
242 is_00 = 0;
243 if (d[i] != 0xFF)
244 is_ff = 0;
245 }
246
247 if (is_ff || is_00)
248 return;
249
250 s = dmi_alloc(16*2+4+1);
251 if (!s)
252 return;
253
254 /*
255 * As of version 2.6 of the SMBIOS specification, the first 3 fields of
256 * the UUID are supposed to be little-endian encoded. The specification
257 * says that this is the defacto standard.
258 */
259 if (dmi_ver >= 0x020600)
260 sprintf(s, "%pUl", d);
261 else
262 sprintf(s, "%pUb", d);
263
264 dmi_ident[slot] = s;
265 }
266
dmi_save_type(const struct dmi_header * dm,int slot,int index)267 static void __init dmi_save_type(const struct dmi_header *dm, int slot,
268 int index)
269 {
270 const u8 *d;
271 char *s;
272
273 if (dmi_ident[slot] || dm->length <= index)
274 return;
275
276 s = dmi_alloc(4);
277 if (!s)
278 return;
279
280 d = (u8 *) dm + index;
281 sprintf(s, "%u", *d & 0x7F);
282 dmi_ident[slot] = s;
283 }
284
dmi_save_one_device(int type,const char * name)285 static void __init dmi_save_one_device(int type, const char *name)
286 {
287 struct dmi_device *dev;
288
289 /* No duplicate device */
290 if (dmi_find_device(type, name, NULL))
291 return;
292
293 dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
294 if (!dev)
295 return;
296
297 dev->type = type;
298 strcpy((char *)(dev + 1), name);
299 dev->name = (char *)(dev + 1);
300 dev->device_data = NULL;
301 list_add(&dev->list, &dmi_devices);
302 }
303
dmi_save_devices(const struct dmi_header * dm)304 static void __init dmi_save_devices(const struct dmi_header *dm)
305 {
306 int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
307
308 for (i = 0; i < count; i++) {
309 const char *d = (char *)(dm + 1) + (i * 2);
310
311 /* Skip disabled device */
312 if ((*d & 0x80) == 0)
313 continue;
314
315 dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
316 }
317 }
318
dmi_save_oem_strings_devices(const struct dmi_header * dm)319 static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
320 {
321 int i, count;
322 struct dmi_device *dev;
323
324 if (dm->length < 0x05)
325 return;
326
327 count = *(u8 *)(dm + 1);
328 for (i = 1; i <= count; i++) {
329 const char *devname = dmi_string(dm, i);
330
331 if (devname == dmi_empty_string)
332 continue;
333
334 dev = dmi_alloc(sizeof(*dev));
335 if (!dev)
336 break;
337
338 dev->type = DMI_DEV_TYPE_OEM_STRING;
339 dev->name = devname;
340 dev->device_data = NULL;
341
342 list_add(&dev->list, &dmi_devices);
343 }
344 }
345
dmi_save_ipmi_device(const struct dmi_header * dm)346 static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
347 {
348 struct dmi_device *dev;
349 void *data;
350
351 data = dmi_alloc(dm->length);
352 if (data == NULL)
353 return;
354
355 memcpy(data, dm, dm->length);
356
357 dev = dmi_alloc(sizeof(*dev));
358 if (!dev)
359 return;
360
361 dev->type = DMI_DEV_TYPE_IPMI;
362 dev->name = "IPMI controller";
363 dev->device_data = data;
364
365 list_add_tail(&dev->list, &dmi_devices);
366 }
367
dmi_save_dev_pciaddr(int instance,int segment,int bus,int devfn,const char * name,int type)368 static void __init dmi_save_dev_pciaddr(int instance, int segment, int bus,
369 int devfn, const char *name, int type)
370 {
371 struct dmi_dev_onboard *dev;
372
373 /* Ignore invalid values */
374 if (type == DMI_DEV_TYPE_DEV_SLOT &&
375 segment == 0xFFFF && bus == 0xFF && devfn == 0xFF)
376 return;
377
378 dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
379 if (!dev)
380 return;
381
382 dev->instance = instance;
383 dev->segment = segment;
384 dev->bus = bus;
385 dev->devfn = devfn;
386
387 strcpy((char *)&dev[1], name);
388 dev->dev.type = type;
389 dev->dev.name = (char *)&dev[1];
390 dev->dev.device_data = dev;
391
392 list_add(&dev->dev.list, &dmi_devices);
393 }
394
dmi_save_extended_devices(const struct dmi_header * dm)395 static void __init dmi_save_extended_devices(const struct dmi_header *dm)
396 {
397 const char *name;
398 const u8 *d = (u8 *)dm;
399
400 if (dm->length < 0x0B)
401 return;
402
403 /* Skip disabled device */
404 if ((d[0x5] & 0x80) == 0)
405 return;
406
407 name = dmi_string_nosave(dm, d[0x4]);
408 dmi_save_dev_pciaddr(d[0x6], *(u16 *)(d + 0x7), d[0x9], d[0xA], name,
409 DMI_DEV_TYPE_DEV_ONBOARD);
410 dmi_save_one_device(d[0x5] & 0x7f, name);
411 }
412
dmi_save_system_slot(const struct dmi_header * dm)413 static void __init dmi_save_system_slot(const struct dmi_header *dm)
414 {
415 const u8 *d = (u8 *)dm;
416
417 /* Need SMBIOS 2.6+ structure */
418 if (dm->length < 0x11)
419 return;
420 dmi_save_dev_pciaddr(*(u16 *)(d + 0x9), *(u16 *)(d + 0xD), d[0xF],
421 d[0x10], dmi_string_nosave(dm, d[0x4]),
422 DMI_DEV_TYPE_DEV_SLOT);
423 }
424
count_mem_devices(const struct dmi_header * dm,void * v)425 static void __init count_mem_devices(const struct dmi_header *dm, void *v)
426 {
427 if (dm->type != DMI_ENTRY_MEM_DEVICE)
428 return;
429 dmi_memdev_nr++;
430 }
431
save_mem_devices(const struct dmi_header * dm,void * v)432 static void __init save_mem_devices(const struct dmi_header *dm, void *v)
433 {
434 const char *d = (const char *)dm;
435 static int nr;
436 u64 bytes;
437 u16 size;
438
439 if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x13)
440 return;
441 if (nr >= dmi_memdev_nr) {
442 pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
443 return;
444 }
445 dmi_memdev[nr].handle = get_unaligned(&dm->handle);
446 dmi_memdev[nr].device = dmi_string(dm, d[0x10]);
447 dmi_memdev[nr].bank = dmi_string(dm, d[0x11]);
448 dmi_memdev[nr].type = d[0x12];
449
450 size = get_unaligned((u16 *)&d[0xC]);
451 if (size == 0)
452 bytes = 0;
453 else if (size == 0xffff)
454 bytes = ~0ull;
455 else if (size & 0x8000)
456 bytes = (u64)(size & 0x7fff) << 10;
457 else if (size != 0x7fff || dm->length < 0x20)
458 bytes = (u64)size << 20;
459 else
460 bytes = (u64)get_unaligned((u32 *)&d[0x1C]) << 20;
461
462 dmi_memdev[nr].size = bytes;
463 nr++;
464 }
465
dmi_memdev_walk(void)466 static void __init dmi_memdev_walk(void)
467 {
468 if (dmi_walk_early(count_mem_devices) == 0 && dmi_memdev_nr) {
469 dmi_memdev = dmi_alloc(sizeof(*dmi_memdev) * dmi_memdev_nr);
470 if (dmi_memdev)
471 dmi_walk_early(save_mem_devices);
472 }
473 }
474
475 /*
476 * Process a DMI table entry. Right now all we care about are the BIOS
477 * and machine entries. For 2.5 we should pull the smbus controller info
478 * out of here.
479 */
dmi_decode(const struct dmi_header * dm,void * dummy)480 static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
481 {
482 switch (dm->type) {
483 case 0: /* BIOS Information */
484 dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
485 dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
486 dmi_save_ident(dm, DMI_BIOS_DATE, 8);
487 dmi_save_release(dm, DMI_BIOS_RELEASE, 21);
488 dmi_save_release(dm, DMI_EC_FIRMWARE_RELEASE, 23);
489 break;
490 case 1: /* System Information */
491 dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
492 dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
493 dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
494 dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
495 dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
496 dmi_save_ident(dm, DMI_PRODUCT_SKU, 25);
497 dmi_save_ident(dm, DMI_PRODUCT_FAMILY, 26);
498 break;
499 case 2: /* Base Board Information */
500 dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
501 dmi_save_ident(dm, DMI_BOARD_NAME, 5);
502 dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
503 dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
504 dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
505 break;
506 case 3: /* Chassis Information */
507 dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
508 dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
509 dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
510 dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
511 dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
512 break;
513 case 9: /* System Slots */
514 dmi_save_system_slot(dm);
515 break;
516 case 10: /* Onboard Devices Information */
517 dmi_save_devices(dm);
518 break;
519 case 11: /* OEM Strings */
520 dmi_save_oem_strings_devices(dm);
521 break;
522 case 38: /* IPMI Device Information */
523 dmi_save_ipmi_device(dm);
524 break;
525 case 41: /* Onboard Devices Extended Information */
526 dmi_save_extended_devices(dm);
527 }
528 }
529
print_filtered(char * buf,size_t len,const char * info)530 static int __init print_filtered(char *buf, size_t len, const char *info)
531 {
532 int c = 0;
533 const char *p;
534
535 if (!info)
536 return c;
537
538 for (p = info; *p; p++)
539 if (isprint(*p))
540 c += scnprintf(buf + c, len - c, "%c", *p);
541 else
542 c += scnprintf(buf + c, len - c, "\\x%02x", *p & 0xff);
543 return c;
544 }
545
dmi_format_ids(char * buf,size_t len)546 static void __init dmi_format_ids(char *buf, size_t len)
547 {
548 int c = 0;
549 const char *board; /* Board Name is optional */
550
551 c += print_filtered(buf + c, len - c,
552 dmi_get_system_info(DMI_SYS_VENDOR));
553 c += scnprintf(buf + c, len - c, " ");
554 c += print_filtered(buf + c, len - c,
555 dmi_get_system_info(DMI_PRODUCT_NAME));
556
557 board = dmi_get_system_info(DMI_BOARD_NAME);
558 if (board) {
559 c += scnprintf(buf + c, len - c, "/");
560 c += print_filtered(buf + c, len - c, board);
561 }
562 c += scnprintf(buf + c, len - c, ", BIOS ");
563 c += print_filtered(buf + c, len - c,
564 dmi_get_system_info(DMI_BIOS_VERSION));
565 c += scnprintf(buf + c, len - c, " ");
566 c += print_filtered(buf + c, len - c,
567 dmi_get_system_info(DMI_BIOS_DATE));
568 }
569
570 /*
571 * Check for DMI/SMBIOS headers in the system firmware image. Any
572 * SMBIOS header must start 16 bytes before the DMI header, so take a
573 * 32 byte buffer and check for DMI at offset 16 and SMBIOS at offset
574 * 0. If the DMI header is present, set dmi_ver accordingly (SMBIOS
575 * takes precedence) and return 0. Otherwise return 1.
576 */
dmi_present(const u8 * buf)577 static int __init dmi_present(const u8 *buf)
578 {
579 u32 smbios_ver;
580
581 /*
582 * The size of this structure is 31 bytes, but we also accept value
583 * 30 due to a mistake in SMBIOS specification version 2.1.
584 */
585 if (memcmp(buf, "_SM_", 4) == 0 &&
586 buf[5] >= 30 && buf[5] <= 32 &&
587 dmi_checksum(buf, buf[5])) {
588 smbios_ver = get_unaligned_be16(buf + 6);
589 smbios_entry_point_size = buf[5];
590 memcpy(smbios_entry_point, buf, smbios_entry_point_size);
591
592 /* Some BIOS report weird SMBIOS version, fix that up */
593 switch (smbios_ver) {
594 case 0x021F:
595 case 0x0221:
596 pr_debug("SMBIOS version fixup (2.%d->2.%d)\n",
597 smbios_ver & 0xFF, 3);
598 smbios_ver = 0x0203;
599 break;
600 case 0x0233:
601 pr_debug("SMBIOS version fixup (2.%d->2.%d)\n", 51, 6);
602 smbios_ver = 0x0206;
603 break;
604 }
605 } else {
606 smbios_ver = 0;
607 }
608
609 buf += 16;
610
611 if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {
612 if (smbios_ver)
613 dmi_ver = smbios_ver;
614 else
615 dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F);
616 dmi_ver <<= 8;
617 dmi_num = get_unaligned_le16(buf + 12);
618 dmi_len = get_unaligned_le16(buf + 6);
619 dmi_base = get_unaligned_le32(buf + 8);
620
621 if (dmi_walk_early(dmi_decode) == 0) {
622 if (smbios_ver) {
623 pr_info("SMBIOS %d.%d present.\n",
624 dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
625 } else {
626 smbios_entry_point_size = 15;
627 memcpy(smbios_entry_point, buf,
628 smbios_entry_point_size);
629 pr_info("Legacy DMI %d.%d present.\n",
630 dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
631 }
632 dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
633 pr_info("DMI: %s\n", dmi_ids_string);
634 return 0;
635 }
636 }
637
638 return 1;
639 }
640
641 /*
642 * Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy
643 * 32-bit entry point, there is no embedded DMI header (_DMI_) in here.
644 */
dmi_smbios3_present(const u8 * buf)645 static int __init dmi_smbios3_present(const u8 *buf)
646 {
647 if (memcmp(buf, "_SM3_", 5) == 0 &&
648 buf[6] >= 24 && buf[6] <= 32 &&
649 dmi_checksum(buf, buf[6])) {
650 dmi_ver = get_unaligned_be24(buf + 7);
651 dmi_num = 0; /* No longer specified */
652 dmi_len = get_unaligned_le32(buf + 12);
653 dmi_base = get_unaligned_le64(buf + 16);
654 smbios_entry_point_size = buf[6];
655 memcpy(smbios_entry_point, buf, smbios_entry_point_size);
656
657 if (dmi_walk_early(dmi_decode) == 0) {
658 pr_info("SMBIOS %d.%d.%d present.\n",
659 dmi_ver >> 16, (dmi_ver >> 8) & 0xFF,
660 dmi_ver & 0xFF);
661 dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
662 pr_info("DMI: %s\n", dmi_ids_string);
663 return 0;
664 }
665 }
666 return 1;
667 }
668
dmi_scan_machine(void)669 static void __init dmi_scan_machine(void)
670 {
671 char __iomem *p, *q;
672 char buf[32];
673
674 if (efi_enabled(EFI_CONFIG_TABLES)) {
675 /*
676 * According to the DMTF SMBIOS reference spec v3.0.0, it is
677 * allowed to define both the 64-bit entry point (smbios3) and
678 * the 32-bit entry point (smbios), in which case they should
679 * either both point to the same SMBIOS structure table, or the
680 * table pointed to by the 64-bit entry point should contain a
681 * superset of the table contents pointed to by the 32-bit entry
682 * point (section 5.2)
683 * This implies that the 64-bit entry point should have
684 * precedence if it is defined and supported by the OS. If we
685 * have the 64-bit entry point, but fail to decode it, fall
686 * back to the legacy one (if available)
687 */
688 if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) {
689 p = dmi_early_remap(efi.smbios3, 32);
690 if (p == NULL)
691 goto error;
692 memcpy_fromio(buf, p, 32);
693 dmi_early_unmap(p, 32);
694
695 if (!dmi_smbios3_present(buf)) {
696 dmi_available = 1;
697 return;
698 }
699 }
700 if (efi.smbios == EFI_INVALID_TABLE_ADDR)
701 goto error;
702
703 /* This is called as a core_initcall() because it isn't
704 * needed during early boot. This also means we can
705 * iounmap the space when we're done with it.
706 */
707 p = dmi_early_remap(efi.smbios, 32);
708 if (p == NULL)
709 goto error;
710 memcpy_fromio(buf, p, 32);
711 dmi_early_unmap(p, 32);
712
713 if (!dmi_present(buf)) {
714 dmi_available = 1;
715 return;
716 }
717 } else if (IS_ENABLED(CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK)) {
718 p = dmi_early_remap(SMBIOS_ENTRY_POINT_SCAN_START, 0x10000);
719 if (p == NULL)
720 goto error;
721
722 /*
723 * Same logic as above, look for a 64-bit entry point
724 * first, and if not found, fall back to 32-bit entry point.
725 */
726 memcpy_fromio(buf, p, 16);
727 for (q = p + 16; q < p + 0x10000; q += 16) {
728 memcpy_fromio(buf + 16, q, 16);
729 if (!dmi_smbios3_present(buf)) {
730 dmi_available = 1;
731 dmi_early_unmap(p, 0x10000);
732 return;
733 }
734 memcpy(buf, buf + 16, 16);
735 }
736
737 /*
738 * Iterate over all possible DMI header addresses q.
739 * Maintain the 32 bytes around q in buf. On the
740 * first iteration, substitute zero for the
741 * out-of-range bytes so there is no chance of falsely
742 * detecting an SMBIOS header.
743 */
744 memset(buf, 0, 16);
745 for (q = p; q < p + 0x10000; q += 16) {
746 memcpy_fromio(buf + 16, q, 16);
747 if (!dmi_present(buf)) {
748 dmi_available = 1;
749 dmi_early_unmap(p, 0x10000);
750 return;
751 }
752 memcpy(buf, buf + 16, 16);
753 }
754 dmi_early_unmap(p, 0x10000);
755 }
756 error:
757 pr_info("DMI not present or invalid.\n");
758 }
759
raw_table_read(struct file * file,struct kobject * kobj,struct bin_attribute * attr,char * buf,loff_t pos,size_t count)760 static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
761 struct bin_attribute *attr, char *buf,
762 loff_t pos, size_t count)
763 {
764 memcpy(buf, attr->private + pos, count);
765 return count;
766 }
767
768 static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0);
769 static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0);
770
dmi_init(void)771 static int __init dmi_init(void)
772 {
773 struct kobject *tables_kobj;
774 u8 *dmi_table;
775 int ret = -ENOMEM;
776
777 if (!dmi_available)
778 return 0;
779
780 /*
781 * Set up dmi directory at /sys/firmware/dmi. This entry should stay
782 * even after farther error, as it can be used by other modules like
783 * dmi-sysfs.
784 */
785 dmi_kobj = kobject_create_and_add("dmi", firmware_kobj);
786 if (!dmi_kobj)
787 goto err;
788
789 tables_kobj = kobject_create_and_add("tables", dmi_kobj);
790 if (!tables_kobj)
791 goto err;
792
793 dmi_table = dmi_remap(dmi_base, dmi_len);
794 if (!dmi_table)
795 goto err_tables;
796
797 bin_attr_smbios_entry_point.size = smbios_entry_point_size;
798 bin_attr_smbios_entry_point.private = smbios_entry_point;
799 ret = sysfs_create_bin_file(tables_kobj, &bin_attr_smbios_entry_point);
800 if (ret)
801 goto err_unmap;
802
803 bin_attr_DMI.size = dmi_len;
804 bin_attr_DMI.private = dmi_table;
805 ret = sysfs_create_bin_file(tables_kobj, &bin_attr_DMI);
806 if (!ret)
807 return 0;
808
809 sysfs_remove_bin_file(tables_kobj,
810 &bin_attr_smbios_entry_point);
811 err_unmap:
812 dmi_unmap(dmi_table);
813 err_tables:
814 kobject_del(tables_kobj);
815 kobject_put(tables_kobj);
816 err:
817 pr_err("dmi: Firmware registration failed.\n");
818
819 return ret;
820 }
821 subsys_initcall(dmi_init);
822
823 /**
824 * dmi_setup - scan and setup DMI system information
825 *
826 * Scan the DMI system information. This setups DMI identifiers
827 * (dmi_system_id) for printing it out on task dumps and prepares
828 * DIMM entry information (dmi_memdev_info) from the SMBIOS table
829 * for using this when reporting memory errors.
830 */
dmi_setup(void)831 void __init dmi_setup(void)
832 {
833 dmi_scan_machine();
834 if (!dmi_available)
835 return;
836
837 dmi_memdev_walk();
838 dump_stack_set_arch_desc("%s", dmi_ids_string);
839 }
840
841 /**
842 * dmi_matches - check if dmi_system_id structure matches system DMI data
843 * @dmi: pointer to the dmi_system_id structure to check
844 */
dmi_matches(const struct dmi_system_id * dmi)845 static bool dmi_matches(const struct dmi_system_id *dmi)
846 {
847 int i;
848
849 for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
850 int s = dmi->matches[i].slot;
851 if (s == DMI_NONE)
852 break;
853 if (s == DMI_OEM_STRING) {
854 /* DMI_OEM_STRING must be exact match */
855 const struct dmi_device *valid;
856
857 valid = dmi_find_device(DMI_DEV_TYPE_OEM_STRING,
858 dmi->matches[i].substr, NULL);
859 if (valid)
860 continue;
861 } else if (dmi_ident[s]) {
862 if (dmi->matches[i].exact_match) {
863 if (!strcmp(dmi_ident[s],
864 dmi->matches[i].substr))
865 continue;
866 } else {
867 if (strstr(dmi_ident[s],
868 dmi->matches[i].substr))
869 continue;
870 }
871 }
872
873 /* No match */
874 return false;
875 }
876 return true;
877 }
878
879 /**
880 * dmi_is_end_of_table - check for end-of-table marker
881 * @dmi: pointer to the dmi_system_id structure to check
882 */
dmi_is_end_of_table(const struct dmi_system_id * dmi)883 static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
884 {
885 return dmi->matches[0].slot == DMI_NONE;
886 }
887
888 /**
889 * dmi_check_system - check system DMI data
890 * @list: array of dmi_system_id structures to match against
891 * All non-null elements of the list must match
892 * their slot's (field index's) data (i.e., each
893 * list string must be a substring of the specified
894 * DMI slot's string data) to be considered a
895 * successful match.
896 *
897 * Walk the blacklist table running matching functions until someone
898 * returns non zero or we hit the end. Callback function is called for
899 * each successful match. Returns the number of matches.
900 *
901 * dmi_setup must be called before this function is called.
902 */
dmi_check_system(const struct dmi_system_id * list)903 int dmi_check_system(const struct dmi_system_id *list)
904 {
905 int count = 0;
906 const struct dmi_system_id *d;
907
908 for (d = list; !dmi_is_end_of_table(d); d++)
909 if (dmi_matches(d)) {
910 count++;
911 if (d->callback && d->callback(d))
912 break;
913 }
914
915 return count;
916 }
917 EXPORT_SYMBOL(dmi_check_system);
918
919 /**
920 * dmi_first_match - find dmi_system_id structure matching system DMI data
921 * @list: array of dmi_system_id structures to match against
922 * All non-null elements of the list must match
923 * their slot's (field index's) data (i.e., each
924 * list string must be a substring of the specified
925 * DMI slot's string data) to be considered a
926 * successful match.
927 *
928 * Walk the blacklist table until the first match is found. Return the
929 * pointer to the matching entry or NULL if there's no match.
930 *
931 * dmi_setup must be called before this function is called.
932 */
dmi_first_match(const struct dmi_system_id * list)933 const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
934 {
935 const struct dmi_system_id *d;
936
937 for (d = list; !dmi_is_end_of_table(d); d++)
938 if (dmi_matches(d))
939 return d;
940
941 return NULL;
942 }
943 EXPORT_SYMBOL(dmi_first_match);
944
945 /**
946 * dmi_get_system_info - return DMI data value
947 * @field: data index (see enum dmi_field)
948 *
949 * Returns one DMI data value, can be used to perform
950 * complex DMI data checks.
951 */
dmi_get_system_info(int field)952 const char *dmi_get_system_info(int field)
953 {
954 return dmi_ident[field];
955 }
956 EXPORT_SYMBOL(dmi_get_system_info);
957
958 /**
959 * dmi_name_in_serial - Check if string is in the DMI product serial information
960 * @str: string to check for
961 */
dmi_name_in_serial(const char * str)962 int dmi_name_in_serial(const char *str)
963 {
964 int f = DMI_PRODUCT_SERIAL;
965 if (dmi_ident[f] && strstr(dmi_ident[f], str))
966 return 1;
967 return 0;
968 }
969
970 /**
971 * dmi_name_in_vendors - Check if string is in the DMI system or board vendor name
972 * @str: Case sensitive Name
973 */
dmi_name_in_vendors(const char * str)974 int dmi_name_in_vendors(const char *str)
975 {
976 static int fields[] = { DMI_SYS_VENDOR, DMI_BOARD_VENDOR, DMI_NONE };
977 int i;
978 for (i = 0; fields[i] != DMI_NONE; i++) {
979 int f = fields[i];
980 if (dmi_ident[f] && strstr(dmi_ident[f], str))
981 return 1;
982 }
983 return 0;
984 }
985 EXPORT_SYMBOL(dmi_name_in_vendors);
986
987 /**
988 * dmi_find_device - find onboard device by type/name
989 * @type: device type or %DMI_DEV_TYPE_ANY to match all device types
990 * @name: device name string or %NULL to match all
991 * @from: previous device found in search, or %NULL for new search.
992 *
993 * Iterates through the list of known onboard devices. If a device is
994 * found with a matching @type and @name, a pointer to its device
995 * structure is returned. Otherwise, %NULL is returned.
996 * A new search is initiated by passing %NULL as the @from argument.
997 * If @from is not %NULL, searches continue from next device.
998 */
dmi_find_device(int type,const char * name,const struct dmi_device * from)999 const struct dmi_device *dmi_find_device(int type, const char *name,
1000 const struct dmi_device *from)
1001 {
1002 const struct list_head *head = from ? &from->list : &dmi_devices;
1003 struct list_head *d;
1004
1005 for (d = head->next; d != &dmi_devices; d = d->next) {
1006 const struct dmi_device *dev =
1007 list_entry(d, struct dmi_device, list);
1008
1009 if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
1010 ((name == NULL) || (strcmp(dev->name, name) == 0)))
1011 return dev;
1012 }
1013
1014 return NULL;
1015 }
1016 EXPORT_SYMBOL(dmi_find_device);
1017
1018 /**
1019 * dmi_get_date - parse a DMI date
1020 * @field: data index (see enum dmi_field)
1021 * @yearp: optional out parameter for the year
1022 * @monthp: optional out parameter for the month
1023 * @dayp: optional out parameter for the day
1024 *
1025 * The date field is assumed to be in the form resembling
1026 * [mm[/dd]]/yy[yy] and the result is stored in the out
1027 * parameters any or all of which can be omitted.
1028 *
1029 * If the field doesn't exist, all out parameters are set to zero
1030 * and false is returned. Otherwise, true is returned with any
1031 * invalid part of date set to zero.
1032 *
1033 * On return, year, month and day are guaranteed to be in the
1034 * range of [0,9999], [0,12] and [0,31] respectively.
1035 */
dmi_get_date(int field,int * yearp,int * monthp,int * dayp)1036 bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
1037 {
1038 int year = 0, month = 0, day = 0;
1039 bool exists;
1040 const char *s, *y;
1041 char *e;
1042
1043 s = dmi_get_system_info(field);
1044 exists = s;
1045 if (!exists)
1046 goto out;
1047
1048 /*
1049 * Determine year first. We assume the date string resembles
1050 * mm/dd/yy[yy] but the original code extracted only the year
1051 * from the end. Keep the behavior in the spirit of no
1052 * surprises.
1053 */
1054 y = strrchr(s, '/');
1055 if (!y)
1056 goto out;
1057
1058 y++;
1059 year = simple_strtoul(y, &e, 10);
1060 if (y != e && year < 100) { /* 2-digit year */
1061 year += 1900;
1062 if (year < 1996) /* no dates < spec 1.0 */
1063 year += 100;
1064 }
1065 if (year > 9999) /* year should fit in %04d */
1066 year = 0;
1067
1068 /* parse the mm and dd */
1069 month = simple_strtoul(s, &e, 10);
1070 if (s == e || *e != '/' || !month || month > 12) {
1071 month = 0;
1072 goto out;
1073 }
1074
1075 s = e + 1;
1076 day = simple_strtoul(s, &e, 10);
1077 if (s == y || s == e || *e != '/' || day > 31)
1078 day = 0;
1079 out:
1080 if (yearp)
1081 *yearp = year;
1082 if (monthp)
1083 *monthp = month;
1084 if (dayp)
1085 *dayp = day;
1086 return exists;
1087 }
1088 EXPORT_SYMBOL(dmi_get_date);
1089
1090 /**
1091 * dmi_get_bios_year - get a year out of DMI_BIOS_DATE field
1092 *
1093 * Returns year on success, -ENXIO if DMI is not selected,
1094 * or a different negative error code if DMI field is not present
1095 * or not parseable.
1096 */
dmi_get_bios_year(void)1097 int dmi_get_bios_year(void)
1098 {
1099 bool exists;
1100 int year;
1101
1102 exists = dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
1103 if (!exists)
1104 return -ENODATA;
1105
1106 return year ? year : -ERANGE;
1107 }
1108 EXPORT_SYMBOL(dmi_get_bios_year);
1109
1110 /**
1111 * dmi_walk - Walk the DMI table and get called back for every record
1112 * @decode: Callback function
1113 * @private_data: Private data to be passed to the callback function
1114 *
1115 * Returns 0 on success, -ENXIO if DMI is not selected or not present,
1116 * or a different negative error code if DMI walking fails.
1117 */
dmi_walk(void (* decode)(const struct dmi_header *,void *),void * private_data)1118 int dmi_walk(void (*decode)(const struct dmi_header *, void *),
1119 void *private_data)
1120 {
1121 u8 *buf;
1122
1123 if (!dmi_available)
1124 return -ENXIO;
1125
1126 buf = dmi_remap(dmi_base, dmi_len);
1127 if (buf == NULL)
1128 return -ENOMEM;
1129
1130 dmi_decode_table(buf, decode, private_data);
1131
1132 dmi_unmap(buf);
1133 return 0;
1134 }
1135 EXPORT_SYMBOL_GPL(dmi_walk);
1136
1137 /**
1138 * dmi_match - compare a string to the dmi field (if exists)
1139 * @f: DMI field identifier
1140 * @str: string to compare the DMI field to
1141 *
1142 * Returns true if the requested field equals to the str (including NULL).
1143 */
dmi_match(enum dmi_field f,const char * str)1144 bool dmi_match(enum dmi_field f, const char *str)
1145 {
1146 const char *info = dmi_get_system_info(f);
1147
1148 if (info == NULL || str == NULL)
1149 return info == str;
1150
1151 return !strcmp(info, str);
1152 }
1153 EXPORT_SYMBOL_GPL(dmi_match);
1154
dmi_memdev_name(u16 handle,const char ** bank,const char ** device)1155 void dmi_memdev_name(u16 handle, const char **bank, const char **device)
1156 {
1157 int n;
1158
1159 if (dmi_memdev == NULL)
1160 return;
1161
1162 for (n = 0; n < dmi_memdev_nr; n++) {
1163 if (handle == dmi_memdev[n].handle) {
1164 *bank = dmi_memdev[n].bank;
1165 *device = dmi_memdev[n].device;
1166 break;
1167 }
1168 }
1169 }
1170 EXPORT_SYMBOL_GPL(dmi_memdev_name);
1171
dmi_memdev_size(u16 handle)1172 u64 dmi_memdev_size(u16 handle)
1173 {
1174 int n;
1175
1176 if (dmi_memdev) {
1177 for (n = 0; n < dmi_memdev_nr; n++) {
1178 if (handle == dmi_memdev[n].handle)
1179 return dmi_memdev[n].size;
1180 }
1181 }
1182 return ~0ull;
1183 }
1184 EXPORT_SYMBOL_GPL(dmi_memdev_size);
1185
1186 /**
1187 * dmi_memdev_type - get the memory type
1188 * @handle: DMI structure handle
1189 *
1190 * Return the DMI memory type of the module in the slot associated with the
1191 * given DMI handle, or 0x0 if no such DMI handle exists.
1192 */
dmi_memdev_type(u16 handle)1193 u8 dmi_memdev_type(u16 handle)
1194 {
1195 int n;
1196
1197 if (dmi_memdev) {
1198 for (n = 0; n < dmi_memdev_nr; n++) {
1199 if (handle == dmi_memdev[n].handle)
1200 return dmi_memdev[n].type;
1201 }
1202 }
1203 return 0x0; /* Not a valid value */
1204 }
1205 EXPORT_SYMBOL_GPL(dmi_memdev_type);
1206
1207 /**
1208 * dmi_memdev_handle - get the DMI handle of a memory slot
1209 * @slot: slot number
1210 *
1211 * Return the DMI handle associated with a given memory slot, or %0xFFFF
1212 * if there is no such slot.
1213 */
dmi_memdev_handle(int slot)1214 u16 dmi_memdev_handle(int slot)
1215 {
1216 if (dmi_memdev && slot >= 0 && slot < dmi_memdev_nr)
1217 return dmi_memdev[slot].handle;
1218
1219 return 0xffff; /* Not a valid value */
1220 }
1221 EXPORT_SYMBOL_GPL(dmi_memdev_handle);
1222