xref: /linux/drivers/firmware/dmi_scan.c (revision b83deaa741558babf4b8d51d34f6637ccfff1b26)
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 
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 
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  */
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 		 *  We want to know the total length (formatted area and
106 		 *  strings) before decoding to make sure we won't run off the
107 		 *  table in dmi_decode or dmi_string
108 		 */
109 		data += dm->length;
110 		while ((data - buf < dmi_len - 1) && (data[0] || data[1]))
111 			data++;
112 		if (data - buf < dmi_len - 1)
113 			decode(dm, private_data);
114 
115 		data += 2;
116 		i++;
117 
118 		/*
119 		 * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
120 		 * For tables behind a 64-bit entry point, we have no item
121 		 * count and no exact table length, so stop on end-of-table
122 		 * marker. For tables behind a 32-bit entry point, we have
123 		 * seen OEM structures behind the end-of-table marker on
124 		 * some systems, so don't trust it.
125 		 */
126 		if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE)
127 			break;
128 	}
129 
130 	/* Trim DMI table length if needed */
131 	if (dmi_len > data - buf)
132 		dmi_len = data - buf;
133 }
134 
135 static phys_addr_t dmi_base;
136 
137 static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
138 		void *))
139 {
140 	u8 *buf;
141 	u32 orig_dmi_len = dmi_len;
142 
143 	buf = dmi_early_remap(dmi_base, orig_dmi_len);
144 	if (buf == NULL)
145 		return -ENOMEM;
146 
147 	dmi_decode_table(buf, decode, NULL);
148 
149 	add_device_randomness(buf, dmi_len);
150 
151 	dmi_early_unmap(buf, orig_dmi_len);
152 	return 0;
153 }
154 
155 static int __init dmi_checksum(const u8 *buf, u8 len)
156 {
157 	u8 sum = 0;
158 	int a;
159 
160 	for (a = 0; a < len; a++)
161 		sum += buf[a];
162 
163 	return sum == 0;
164 }
165 
166 static const char *dmi_ident[DMI_STRING_MAX];
167 static LIST_HEAD(dmi_devices);
168 int dmi_available;
169 EXPORT_SYMBOL_GPL(dmi_available);
170 
171 /*
172  *	Save a DMI string
173  */
174 static void __init dmi_save_ident(const struct dmi_header *dm, int slot,
175 		int string)
176 {
177 	const char *d = (const char *) dm;
178 	const char *p;
179 
180 	if (dmi_ident[slot] || dm->length <= string)
181 		return;
182 
183 	p = dmi_string(dm, d[string]);
184 	if (p == NULL)
185 		return;
186 
187 	dmi_ident[slot] = p;
188 }
189 
190 static void __init dmi_save_release(const struct dmi_header *dm, int slot,
191 		int index)
192 {
193 	const u8 *minor, *major;
194 	char *s;
195 
196 	/* If the table doesn't have the field, let's return */
197 	if (dmi_ident[slot] || dm->length < index)
198 		return;
199 
200 	minor = (u8 *) dm + index;
201 	major = (u8 *) dm + index - 1;
202 
203 	/* As per the spec, if the system doesn't support this field,
204 	 * the value is FF
205 	 */
206 	if (*major == 0xFF && *minor == 0xFF)
207 		return;
208 
209 	s = dmi_alloc(8);
210 	if (!s)
211 		return;
212 
213 	sprintf(s, "%u.%u", *major, *minor);
214 
215 	dmi_ident[slot] = s;
216 }
217 
218 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
219 		int index)
220 {
221 	const u8 *d;
222 	char *s;
223 	int is_ff = 1, is_00 = 1, i;
224 
225 	if (dmi_ident[slot] || dm->length < index + 16)
226 		return;
227 
228 	d = (u8 *) dm + index;
229 	for (i = 0; i < 16 && (is_ff || is_00); i++) {
230 		if (d[i] != 0x00)
231 			is_00 = 0;
232 		if (d[i] != 0xFF)
233 			is_ff = 0;
234 	}
235 
236 	if (is_ff || is_00)
237 		return;
238 
239 	s = dmi_alloc(16*2+4+1);
240 	if (!s)
241 		return;
242 
243 	/*
244 	 * As of version 2.6 of the SMBIOS specification, the first 3 fields of
245 	 * the UUID are supposed to be little-endian encoded.  The specification
246 	 * says that this is the defacto standard.
247 	 */
248 	if (dmi_ver >= 0x020600)
249 		sprintf(s, "%pUl", d);
250 	else
251 		sprintf(s, "%pUb", d);
252 
253 	dmi_ident[slot] = s;
254 }
255 
256 static void __init dmi_save_type(const struct dmi_header *dm, int slot,
257 		int index)
258 {
259 	const u8 *d;
260 	char *s;
261 
262 	if (dmi_ident[slot] || dm->length <= index)
263 		return;
264 
265 	s = dmi_alloc(4);
266 	if (!s)
267 		return;
268 
269 	d = (u8 *) dm + index;
270 	sprintf(s, "%u", *d & 0x7F);
271 	dmi_ident[slot] = s;
272 }
273 
274 static void __init dmi_save_one_device(int type, const char *name)
275 {
276 	struct dmi_device *dev;
277 
278 	/* No duplicate device */
279 	if (dmi_find_device(type, name, NULL))
280 		return;
281 
282 	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
283 	if (!dev)
284 		return;
285 
286 	dev->type = type;
287 	strcpy((char *)(dev + 1), name);
288 	dev->name = (char *)(dev + 1);
289 	dev->device_data = NULL;
290 	list_add(&dev->list, &dmi_devices);
291 }
292 
293 static void __init dmi_save_devices(const struct dmi_header *dm)
294 {
295 	int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
296 
297 	for (i = 0; i < count; i++) {
298 		const char *d = (char *)(dm + 1) + (i * 2);
299 
300 		/* Skip disabled device */
301 		if ((*d & 0x80) == 0)
302 			continue;
303 
304 		dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
305 	}
306 }
307 
308 static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
309 {
310 	int i, count;
311 	struct dmi_device *dev;
312 
313 	if (dm->length < 0x05)
314 		return;
315 
316 	count = *(u8 *)(dm + 1);
317 	for (i = 1; i <= count; i++) {
318 		const char *devname = dmi_string(dm, i);
319 
320 		if (devname == dmi_empty_string)
321 			continue;
322 
323 		dev = dmi_alloc(sizeof(*dev));
324 		if (!dev)
325 			break;
326 
327 		dev->type = DMI_DEV_TYPE_OEM_STRING;
328 		dev->name = devname;
329 		dev->device_data = NULL;
330 
331 		list_add(&dev->list, &dmi_devices);
332 	}
333 }
334 
335 static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
336 {
337 	struct dmi_device *dev;
338 	void *data;
339 
340 	data = dmi_alloc(dm->length);
341 	if (data == NULL)
342 		return;
343 
344 	memcpy(data, dm, dm->length);
345 
346 	dev = dmi_alloc(sizeof(*dev));
347 	if (!dev)
348 		return;
349 
350 	dev->type = DMI_DEV_TYPE_IPMI;
351 	dev->name = "IPMI controller";
352 	dev->device_data = data;
353 
354 	list_add_tail(&dev->list, &dmi_devices);
355 }
356 
357 static void __init dmi_save_dev_pciaddr(int instance, int segment, int bus,
358 					int devfn, const char *name, int type)
359 {
360 	struct dmi_dev_onboard *dev;
361 
362 	/* Ignore invalid values */
363 	if (type == DMI_DEV_TYPE_DEV_SLOT &&
364 	    segment == 0xFFFF && bus == 0xFF && devfn == 0xFF)
365 		return;
366 
367 	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
368 	if (!dev)
369 		return;
370 
371 	dev->instance = instance;
372 	dev->segment = segment;
373 	dev->bus = bus;
374 	dev->devfn = devfn;
375 
376 	strcpy((char *)&dev[1], name);
377 	dev->dev.type = type;
378 	dev->dev.name = (char *)&dev[1];
379 	dev->dev.device_data = dev;
380 
381 	list_add(&dev->dev.list, &dmi_devices);
382 }
383 
384 static void __init dmi_save_extended_devices(const struct dmi_header *dm)
385 {
386 	const char *name;
387 	const u8 *d = (u8 *)dm;
388 
389 	if (dm->length < 0x0B)
390 		return;
391 
392 	/* Skip disabled device */
393 	if ((d[0x5] & 0x80) == 0)
394 		return;
395 
396 	name = dmi_string_nosave(dm, d[0x4]);
397 	dmi_save_dev_pciaddr(d[0x6], *(u16 *)(d + 0x7), d[0x9], d[0xA], name,
398 			     DMI_DEV_TYPE_DEV_ONBOARD);
399 	dmi_save_one_device(d[0x5] & 0x7f, name);
400 }
401 
402 static void __init dmi_save_system_slot(const struct dmi_header *dm)
403 {
404 	const u8 *d = (u8 *)dm;
405 
406 	/* Need SMBIOS 2.6+ structure */
407 	if (dm->length < 0x11)
408 		return;
409 	dmi_save_dev_pciaddr(*(u16 *)(d + 0x9), *(u16 *)(d + 0xD), d[0xF],
410 			     d[0x10], dmi_string_nosave(dm, d[0x4]),
411 			     DMI_DEV_TYPE_DEV_SLOT);
412 }
413 
414 static void __init count_mem_devices(const struct dmi_header *dm, void *v)
415 {
416 	if (dm->type != DMI_ENTRY_MEM_DEVICE)
417 		return;
418 	dmi_memdev_nr++;
419 }
420 
421 static void __init save_mem_devices(const struct dmi_header *dm, void *v)
422 {
423 	const char *d = (const char *)dm;
424 	static int nr;
425 	u64 bytes;
426 	u16 size;
427 
428 	if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x13)
429 		return;
430 	if (nr >= dmi_memdev_nr) {
431 		pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
432 		return;
433 	}
434 	dmi_memdev[nr].handle = get_unaligned(&dm->handle);
435 	dmi_memdev[nr].device = dmi_string(dm, d[0x10]);
436 	dmi_memdev[nr].bank = dmi_string(dm, d[0x11]);
437 	dmi_memdev[nr].type = d[0x12];
438 
439 	size = get_unaligned((u16 *)&d[0xC]);
440 	if (size == 0)
441 		bytes = 0;
442 	else if (size == 0xffff)
443 		bytes = ~0ull;
444 	else if (size & 0x8000)
445 		bytes = (u64)(size & 0x7fff) << 10;
446 	else if (size != 0x7fff || dm->length < 0x20)
447 		bytes = (u64)size << 20;
448 	else
449 		bytes = (u64)get_unaligned((u32 *)&d[0x1C]) << 20;
450 
451 	dmi_memdev[nr].size = bytes;
452 	nr++;
453 }
454 
455 static void __init dmi_memdev_walk(void)
456 {
457 	if (dmi_walk_early(count_mem_devices) == 0 && dmi_memdev_nr) {
458 		dmi_memdev = dmi_alloc(sizeof(*dmi_memdev) * dmi_memdev_nr);
459 		if (dmi_memdev)
460 			dmi_walk_early(save_mem_devices);
461 	}
462 }
463 
464 /*
465  *	Process a DMI table entry. Right now all we care about are the BIOS
466  *	and machine entries. For 2.5 we should pull the smbus controller info
467  *	out of here.
468  */
469 static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
470 {
471 	switch (dm->type) {
472 	case 0:		/* BIOS Information */
473 		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
474 		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
475 		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
476 		dmi_save_release(dm, DMI_BIOS_RELEASE, 21);
477 		dmi_save_release(dm, DMI_EC_FIRMWARE_RELEASE, 23);
478 		break;
479 	case 1:		/* System Information */
480 		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
481 		dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
482 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
483 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
484 		dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
485 		dmi_save_ident(dm, DMI_PRODUCT_SKU, 25);
486 		dmi_save_ident(dm, DMI_PRODUCT_FAMILY, 26);
487 		break;
488 	case 2:		/* Base Board Information */
489 		dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
490 		dmi_save_ident(dm, DMI_BOARD_NAME, 5);
491 		dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
492 		dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
493 		dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
494 		break;
495 	case 3:		/* Chassis Information */
496 		dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
497 		dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
498 		dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
499 		dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
500 		dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
501 		break;
502 	case 9:		/* System Slots */
503 		dmi_save_system_slot(dm);
504 		break;
505 	case 10:	/* Onboard Devices Information */
506 		dmi_save_devices(dm);
507 		break;
508 	case 11:	/* OEM Strings */
509 		dmi_save_oem_strings_devices(dm);
510 		break;
511 	case 38:	/* IPMI Device Information */
512 		dmi_save_ipmi_device(dm);
513 		break;
514 	case 41:	/* Onboard Devices Extended Information */
515 		dmi_save_extended_devices(dm);
516 	}
517 }
518 
519 static int __init print_filtered(char *buf, size_t len, const char *info)
520 {
521 	int c = 0;
522 	const char *p;
523 
524 	if (!info)
525 		return c;
526 
527 	for (p = info; *p; p++)
528 		if (isprint(*p))
529 			c += scnprintf(buf + c, len - c, "%c", *p);
530 		else
531 			c += scnprintf(buf + c, len - c, "\\x%02x", *p & 0xff);
532 	return c;
533 }
534 
535 static void __init dmi_format_ids(char *buf, size_t len)
536 {
537 	int c = 0;
538 	const char *board;	/* Board Name is optional */
539 
540 	c += print_filtered(buf + c, len - c,
541 			    dmi_get_system_info(DMI_SYS_VENDOR));
542 	c += scnprintf(buf + c, len - c, " ");
543 	c += print_filtered(buf + c, len - c,
544 			    dmi_get_system_info(DMI_PRODUCT_NAME));
545 
546 	board = dmi_get_system_info(DMI_BOARD_NAME);
547 	if (board) {
548 		c += scnprintf(buf + c, len - c, "/");
549 		c += print_filtered(buf + c, len - c, board);
550 	}
551 	c += scnprintf(buf + c, len - c, ", BIOS ");
552 	c += print_filtered(buf + c, len - c,
553 			    dmi_get_system_info(DMI_BIOS_VERSION));
554 	c += scnprintf(buf + c, len - c, " ");
555 	c += print_filtered(buf + c, len - c,
556 			    dmi_get_system_info(DMI_BIOS_DATE));
557 }
558 
559 /*
560  * Check for DMI/SMBIOS headers in the system firmware image.  Any
561  * SMBIOS header must start 16 bytes before the DMI header, so take a
562  * 32 byte buffer and check for DMI at offset 16 and SMBIOS at offset
563  * 0.  If the DMI header is present, set dmi_ver accordingly (SMBIOS
564  * takes precedence) and return 0.  Otherwise return 1.
565  */
566 static int __init dmi_present(const u8 *buf)
567 {
568 	u32 smbios_ver;
569 
570 	if (memcmp(buf, "_SM_", 4) == 0 &&
571 	    buf[5] < 32 && dmi_checksum(buf, buf[5])) {
572 		smbios_ver = get_unaligned_be16(buf + 6);
573 		smbios_entry_point_size = buf[5];
574 		memcpy(smbios_entry_point, buf, smbios_entry_point_size);
575 
576 		/* Some BIOS report weird SMBIOS version, fix that up */
577 		switch (smbios_ver) {
578 		case 0x021F:
579 		case 0x0221:
580 			pr_debug("SMBIOS version fixup (2.%d->2.%d)\n",
581 				 smbios_ver & 0xFF, 3);
582 			smbios_ver = 0x0203;
583 			break;
584 		case 0x0233:
585 			pr_debug("SMBIOS version fixup (2.%d->2.%d)\n", 51, 6);
586 			smbios_ver = 0x0206;
587 			break;
588 		}
589 	} else {
590 		smbios_ver = 0;
591 	}
592 
593 	buf += 16;
594 
595 	if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {
596 		if (smbios_ver)
597 			dmi_ver = smbios_ver;
598 		else
599 			dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F);
600 		dmi_ver <<= 8;
601 		dmi_num = get_unaligned_le16(buf + 12);
602 		dmi_len = get_unaligned_le16(buf + 6);
603 		dmi_base = get_unaligned_le32(buf + 8);
604 
605 		if (dmi_walk_early(dmi_decode) == 0) {
606 			if (smbios_ver) {
607 				pr_info("SMBIOS %d.%d present.\n",
608 					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
609 			} else {
610 				smbios_entry_point_size = 15;
611 				memcpy(smbios_entry_point, buf,
612 				       smbios_entry_point_size);
613 				pr_info("Legacy DMI %d.%d present.\n",
614 					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
615 			}
616 			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
617 			pr_info("DMI: %s\n", dmi_ids_string);
618 			return 0;
619 		}
620 	}
621 
622 	return 1;
623 }
624 
625 /*
626  * Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy
627  * 32-bit entry point, there is no embedded DMI header (_DMI_) in here.
628  */
629 static int __init dmi_smbios3_present(const u8 *buf)
630 {
631 	if (memcmp(buf, "_SM3_", 5) == 0 &&
632 	    buf[6] < 32 && dmi_checksum(buf, buf[6])) {
633 		dmi_ver = get_unaligned_be32(buf + 6) & 0xFFFFFF;
634 		dmi_num = 0;			/* No longer specified */
635 		dmi_len = get_unaligned_le32(buf + 12);
636 		dmi_base = get_unaligned_le64(buf + 16);
637 		smbios_entry_point_size = buf[6];
638 		memcpy(smbios_entry_point, buf, smbios_entry_point_size);
639 
640 		if (dmi_walk_early(dmi_decode) == 0) {
641 			pr_info("SMBIOS %d.%d.%d present.\n",
642 				dmi_ver >> 16, (dmi_ver >> 8) & 0xFF,
643 				dmi_ver & 0xFF);
644 			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
645 			pr_info("DMI: %s\n", dmi_ids_string);
646 			return 0;
647 		}
648 	}
649 	return 1;
650 }
651 
652 static void __init dmi_scan_machine(void)
653 {
654 	char __iomem *p, *q;
655 	char buf[32];
656 
657 	if (efi_enabled(EFI_CONFIG_TABLES)) {
658 		/*
659 		 * According to the DMTF SMBIOS reference spec v3.0.0, it is
660 		 * allowed to define both the 64-bit entry point (smbios3) and
661 		 * the 32-bit entry point (smbios), in which case they should
662 		 * either both point to the same SMBIOS structure table, or the
663 		 * table pointed to by the 64-bit entry point should contain a
664 		 * superset of the table contents pointed to by the 32-bit entry
665 		 * point (section 5.2)
666 		 * This implies that the 64-bit entry point should have
667 		 * precedence if it is defined and supported by the OS. If we
668 		 * have the 64-bit entry point, but fail to decode it, fall
669 		 * back to the legacy one (if available)
670 		 */
671 		if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) {
672 			p = dmi_early_remap(efi.smbios3, 32);
673 			if (p == NULL)
674 				goto error;
675 			memcpy_fromio(buf, p, 32);
676 			dmi_early_unmap(p, 32);
677 
678 			if (!dmi_smbios3_present(buf)) {
679 				dmi_available = 1;
680 				return;
681 			}
682 		}
683 		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
684 			goto error;
685 
686 		/* This is called as a core_initcall() because it isn't
687 		 * needed during early boot.  This also means we can
688 		 * iounmap the space when we're done with it.
689 		 */
690 		p = dmi_early_remap(efi.smbios, 32);
691 		if (p == NULL)
692 			goto error;
693 		memcpy_fromio(buf, p, 32);
694 		dmi_early_unmap(p, 32);
695 
696 		if (!dmi_present(buf)) {
697 			dmi_available = 1;
698 			return;
699 		}
700 	} else if (IS_ENABLED(CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK)) {
701 		p = dmi_early_remap(SMBIOS_ENTRY_POINT_SCAN_START, 0x10000);
702 		if (p == NULL)
703 			goto error;
704 
705 		/*
706 		 * Same logic as above, look for a 64-bit entry point
707 		 * first, and if not found, fall back to 32-bit entry point.
708 		 */
709 		memcpy_fromio(buf, p, 16);
710 		for (q = p + 16; q < p + 0x10000; q += 16) {
711 			memcpy_fromio(buf + 16, q, 16);
712 			if (!dmi_smbios3_present(buf)) {
713 				dmi_available = 1;
714 				dmi_early_unmap(p, 0x10000);
715 				return;
716 			}
717 			memcpy(buf, buf + 16, 16);
718 		}
719 
720 		/*
721 		 * Iterate over all possible DMI header addresses q.
722 		 * Maintain the 32 bytes around q in buf.  On the
723 		 * first iteration, substitute zero for the
724 		 * out-of-range bytes so there is no chance of falsely
725 		 * detecting an SMBIOS header.
726 		 */
727 		memset(buf, 0, 16);
728 		for (q = p; q < p + 0x10000; q += 16) {
729 			memcpy_fromio(buf + 16, q, 16);
730 			if (!dmi_present(buf)) {
731 				dmi_available = 1;
732 				dmi_early_unmap(p, 0x10000);
733 				return;
734 			}
735 			memcpy(buf, buf + 16, 16);
736 		}
737 		dmi_early_unmap(p, 0x10000);
738 	}
739  error:
740 	pr_info("DMI not present or invalid.\n");
741 }
742 
743 static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
744 			      struct bin_attribute *attr, char *buf,
745 			      loff_t pos, size_t count)
746 {
747 	memcpy(buf, attr->private + pos, count);
748 	return count;
749 }
750 
751 static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0);
752 static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0);
753 
754 static int __init dmi_init(void)
755 {
756 	struct kobject *tables_kobj;
757 	u8 *dmi_table;
758 	int ret = -ENOMEM;
759 
760 	if (!dmi_available)
761 		return 0;
762 
763 	/*
764 	 * Set up dmi directory at /sys/firmware/dmi. This entry should stay
765 	 * even after farther error, as it can be used by other modules like
766 	 * dmi-sysfs.
767 	 */
768 	dmi_kobj = kobject_create_and_add("dmi", firmware_kobj);
769 	if (!dmi_kobj)
770 		goto err;
771 
772 	tables_kobj = kobject_create_and_add("tables", dmi_kobj);
773 	if (!tables_kobj)
774 		goto err;
775 
776 	dmi_table = dmi_remap(dmi_base, dmi_len);
777 	if (!dmi_table)
778 		goto err_tables;
779 
780 	bin_attr_smbios_entry_point.size = smbios_entry_point_size;
781 	bin_attr_smbios_entry_point.private = smbios_entry_point;
782 	ret = sysfs_create_bin_file(tables_kobj, &bin_attr_smbios_entry_point);
783 	if (ret)
784 		goto err_unmap;
785 
786 	bin_attr_DMI.size = dmi_len;
787 	bin_attr_DMI.private = dmi_table;
788 	ret = sysfs_create_bin_file(tables_kobj, &bin_attr_DMI);
789 	if (!ret)
790 		return 0;
791 
792 	sysfs_remove_bin_file(tables_kobj,
793 			      &bin_attr_smbios_entry_point);
794  err_unmap:
795 	dmi_unmap(dmi_table);
796  err_tables:
797 	kobject_del(tables_kobj);
798 	kobject_put(tables_kobj);
799  err:
800 	pr_err("dmi: Firmware registration failed.\n");
801 
802 	return ret;
803 }
804 subsys_initcall(dmi_init);
805 
806 /**
807  *	dmi_setup - scan and setup DMI system information
808  *
809  *	Scan the DMI system information. This setups DMI identifiers
810  *	(dmi_system_id) for printing it out on task dumps and prepares
811  *	DIMM entry information (dmi_memdev_info) from the SMBIOS table
812  *	for using this when reporting memory errors.
813  */
814 void __init dmi_setup(void)
815 {
816 	dmi_scan_machine();
817 	if (!dmi_available)
818 		return;
819 
820 	dmi_memdev_walk();
821 	dump_stack_set_arch_desc("%s", dmi_ids_string);
822 }
823 
824 /**
825  *	dmi_matches - check if dmi_system_id structure matches system DMI data
826  *	@dmi: pointer to the dmi_system_id structure to check
827  */
828 static bool dmi_matches(const struct dmi_system_id *dmi)
829 {
830 	int i;
831 
832 	for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
833 		int s = dmi->matches[i].slot;
834 		if (s == DMI_NONE)
835 			break;
836 		if (s == DMI_OEM_STRING) {
837 			/* DMI_OEM_STRING must be exact match */
838 			const struct dmi_device *valid;
839 
840 			valid = dmi_find_device(DMI_DEV_TYPE_OEM_STRING,
841 						dmi->matches[i].substr, NULL);
842 			if (valid)
843 				continue;
844 		} else if (dmi_ident[s]) {
845 			if (dmi->matches[i].exact_match) {
846 				if (!strcmp(dmi_ident[s],
847 					    dmi->matches[i].substr))
848 					continue;
849 			} else {
850 				if (strstr(dmi_ident[s],
851 					   dmi->matches[i].substr))
852 					continue;
853 			}
854 		}
855 
856 		/* No match */
857 		return false;
858 	}
859 	return true;
860 }
861 
862 /**
863  *	dmi_is_end_of_table - check for end-of-table marker
864  *	@dmi: pointer to the dmi_system_id structure to check
865  */
866 static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
867 {
868 	return dmi->matches[0].slot == DMI_NONE;
869 }
870 
871 /**
872  *	dmi_check_system - check system DMI data
873  *	@list: array of dmi_system_id structures to match against
874  *		All non-null elements of the list must match
875  *		their slot's (field index's) data (i.e., each
876  *		list string must be a substring of the specified
877  *		DMI slot's string data) to be considered a
878  *		successful match.
879  *
880  *	Walk the blacklist table running matching functions until someone
881  *	returns non zero or we hit the end. Callback function is called for
882  *	each successful match. Returns the number of matches.
883  *
884  *	dmi_setup must be called before this function is called.
885  */
886 int dmi_check_system(const struct dmi_system_id *list)
887 {
888 	int count = 0;
889 	const struct dmi_system_id *d;
890 
891 	for (d = list; !dmi_is_end_of_table(d); d++)
892 		if (dmi_matches(d)) {
893 			count++;
894 			if (d->callback && d->callback(d))
895 				break;
896 		}
897 
898 	return count;
899 }
900 EXPORT_SYMBOL(dmi_check_system);
901 
902 /**
903  *	dmi_first_match - find dmi_system_id structure matching system DMI data
904  *	@list: array of dmi_system_id structures to match against
905  *		All non-null elements of the list must match
906  *		their slot's (field index's) data (i.e., each
907  *		list string must be a substring of the specified
908  *		DMI slot's string data) to be considered a
909  *		successful match.
910  *
911  *	Walk the blacklist table until the first match is found.  Return the
912  *	pointer to the matching entry or NULL if there's no match.
913  *
914  *	dmi_setup must be called before this function is called.
915  */
916 const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
917 {
918 	const struct dmi_system_id *d;
919 
920 	for (d = list; !dmi_is_end_of_table(d); d++)
921 		if (dmi_matches(d))
922 			return d;
923 
924 	return NULL;
925 }
926 EXPORT_SYMBOL(dmi_first_match);
927 
928 /**
929  *	dmi_get_system_info - return DMI data value
930  *	@field: data index (see enum dmi_field)
931  *
932  *	Returns one DMI data value, can be used to perform
933  *	complex DMI data checks.
934  */
935 const char *dmi_get_system_info(int field)
936 {
937 	return dmi_ident[field];
938 }
939 EXPORT_SYMBOL(dmi_get_system_info);
940 
941 /**
942  * dmi_name_in_serial - Check if string is in the DMI product serial information
943  * @str: string to check for
944  */
945 int dmi_name_in_serial(const char *str)
946 {
947 	int f = DMI_PRODUCT_SERIAL;
948 	if (dmi_ident[f] && strstr(dmi_ident[f], str))
949 		return 1;
950 	return 0;
951 }
952 
953 /**
954  *	dmi_name_in_vendors - Check if string is in the DMI system or board vendor name
955  *	@str: Case sensitive Name
956  */
957 int dmi_name_in_vendors(const char *str)
958 {
959 	static int fields[] = { DMI_SYS_VENDOR, DMI_BOARD_VENDOR, DMI_NONE };
960 	int i;
961 	for (i = 0; fields[i] != DMI_NONE; i++) {
962 		int f = fields[i];
963 		if (dmi_ident[f] && strstr(dmi_ident[f], str))
964 			return 1;
965 	}
966 	return 0;
967 }
968 EXPORT_SYMBOL(dmi_name_in_vendors);
969 
970 /**
971  *	dmi_find_device - find onboard device by type/name
972  *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
973  *	@name: device name string or %NULL to match all
974  *	@from: previous device found in search, or %NULL for new search.
975  *
976  *	Iterates through the list of known onboard devices. If a device is
977  *	found with a matching @type and @name, a pointer to its device
978  *	structure is returned.  Otherwise, %NULL is returned.
979  *	A new search is initiated by passing %NULL as the @from argument.
980  *	If @from is not %NULL, searches continue from next device.
981  */
982 const struct dmi_device *dmi_find_device(int type, const char *name,
983 				    const struct dmi_device *from)
984 {
985 	const struct list_head *head = from ? &from->list : &dmi_devices;
986 	struct list_head *d;
987 
988 	for (d = head->next; d != &dmi_devices; d = d->next) {
989 		const struct dmi_device *dev =
990 			list_entry(d, struct dmi_device, list);
991 
992 		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
993 		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
994 			return dev;
995 	}
996 
997 	return NULL;
998 }
999 EXPORT_SYMBOL(dmi_find_device);
1000 
1001 /**
1002  *	dmi_get_date - parse a DMI date
1003  *	@field:	data index (see enum dmi_field)
1004  *	@yearp: optional out parameter for the year
1005  *	@monthp: optional out parameter for the month
1006  *	@dayp: optional out parameter for the day
1007  *
1008  *	The date field is assumed to be in the form resembling
1009  *	[mm[/dd]]/yy[yy] and the result is stored in the out
1010  *	parameters any or all of which can be omitted.
1011  *
1012  *	If the field doesn't exist, all out parameters are set to zero
1013  *	and false is returned.  Otherwise, true is returned with any
1014  *	invalid part of date set to zero.
1015  *
1016  *	On return, year, month and day are guaranteed to be in the
1017  *	range of [0,9999], [0,12] and [0,31] respectively.
1018  */
1019 bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
1020 {
1021 	int year = 0, month = 0, day = 0;
1022 	bool exists;
1023 	const char *s, *y;
1024 	char *e;
1025 
1026 	s = dmi_get_system_info(field);
1027 	exists = s;
1028 	if (!exists)
1029 		goto out;
1030 
1031 	/*
1032 	 * Determine year first.  We assume the date string resembles
1033 	 * mm/dd/yy[yy] but the original code extracted only the year
1034 	 * from the end.  Keep the behavior in the spirit of no
1035 	 * surprises.
1036 	 */
1037 	y = strrchr(s, '/');
1038 	if (!y)
1039 		goto out;
1040 
1041 	y++;
1042 	year = simple_strtoul(y, &e, 10);
1043 	if (y != e && year < 100) {	/* 2-digit year */
1044 		year += 1900;
1045 		if (year < 1996)	/* no dates < spec 1.0 */
1046 			year += 100;
1047 	}
1048 	if (year > 9999)		/* year should fit in %04d */
1049 		year = 0;
1050 
1051 	/* parse the mm and dd */
1052 	month = simple_strtoul(s, &e, 10);
1053 	if (s == e || *e != '/' || !month || month > 12) {
1054 		month = 0;
1055 		goto out;
1056 	}
1057 
1058 	s = e + 1;
1059 	day = simple_strtoul(s, &e, 10);
1060 	if (s == y || s == e || *e != '/' || day > 31)
1061 		day = 0;
1062 out:
1063 	if (yearp)
1064 		*yearp = year;
1065 	if (monthp)
1066 		*monthp = month;
1067 	if (dayp)
1068 		*dayp = day;
1069 	return exists;
1070 }
1071 EXPORT_SYMBOL(dmi_get_date);
1072 
1073 /**
1074  *	dmi_get_bios_year - get a year out of DMI_BIOS_DATE field
1075  *
1076  *	Returns year on success, -ENXIO if DMI is not selected,
1077  *	or a different negative error code if DMI field is not present
1078  *	or not parseable.
1079  */
1080 int dmi_get_bios_year(void)
1081 {
1082 	bool exists;
1083 	int year;
1084 
1085 	exists = dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
1086 	if (!exists)
1087 		return -ENODATA;
1088 
1089 	return year ? year : -ERANGE;
1090 }
1091 EXPORT_SYMBOL(dmi_get_bios_year);
1092 
1093 /**
1094  *	dmi_walk - Walk the DMI table and get called back for every record
1095  *	@decode: Callback function
1096  *	@private_data: Private data to be passed to the callback function
1097  *
1098  *	Returns 0 on success, -ENXIO if DMI is not selected or not present,
1099  *	or a different negative error code if DMI walking fails.
1100  */
1101 int dmi_walk(void (*decode)(const struct dmi_header *, void *),
1102 	     void *private_data)
1103 {
1104 	u8 *buf;
1105 
1106 	if (!dmi_available)
1107 		return -ENXIO;
1108 
1109 	buf = dmi_remap(dmi_base, dmi_len);
1110 	if (buf == NULL)
1111 		return -ENOMEM;
1112 
1113 	dmi_decode_table(buf, decode, private_data);
1114 
1115 	dmi_unmap(buf);
1116 	return 0;
1117 }
1118 EXPORT_SYMBOL_GPL(dmi_walk);
1119 
1120 /**
1121  * dmi_match - compare a string to the dmi field (if exists)
1122  * @f: DMI field identifier
1123  * @str: string to compare the DMI field to
1124  *
1125  * Returns true if the requested field equals to the str (including NULL).
1126  */
1127 bool dmi_match(enum dmi_field f, const char *str)
1128 {
1129 	const char *info = dmi_get_system_info(f);
1130 
1131 	if (info == NULL || str == NULL)
1132 		return info == str;
1133 
1134 	return !strcmp(info, str);
1135 }
1136 EXPORT_SYMBOL_GPL(dmi_match);
1137 
1138 void dmi_memdev_name(u16 handle, const char **bank, const char **device)
1139 {
1140 	int n;
1141 
1142 	if (dmi_memdev == NULL)
1143 		return;
1144 
1145 	for (n = 0; n < dmi_memdev_nr; n++) {
1146 		if (handle == dmi_memdev[n].handle) {
1147 			*bank = dmi_memdev[n].bank;
1148 			*device = dmi_memdev[n].device;
1149 			break;
1150 		}
1151 	}
1152 }
1153 EXPORT_SYMBOL_GPL(dmi_memdev_name);
1154 
1155 u64 dmi_memdev_size(u16 handle)
1156 {
1157 	int n;
1158 
1159 	if (dmi_memdev) {
1160 		for (n = 0; n < dmi_memdev_nr; n++) {
1161 			if (handle == dmi_memdev[n].handle)
1162 				return dmi_memdev[n].size;
1163 		}
1164 	}
1165 	return ~0ull;
1166 }
1167 EXPORT_SYMBOL_GPL(dmi_memdev_size);
1168 
1169 /**
1170  * dmi_memdev_type - get the memory type
1171  * @handle: DMI structure handle
1172  *
1173  * Return the DMI memory type of the module in the slot associated with the
1174  * given DMI handle, or 0x0 if no such DMI handle exists.
1175  */
1176 u8 dmi_memdev_type(u16 handle)
1177 {
1178 	int n;
1179 
1180 	if (dmi_memdev) {
1181 		for (n = 0; n < dmi_memdev_nr; n++) {
1182 			if (handle == dmi_memdev[n].handle)
1183 				return dmi_memdev[n].type;
1184 		}
1185 	}
1186 	return 0x0;	/* Not a valid value */
1187 }
1188 EXPORT_SYMBOL_GPL(dmi_memdev_type);
1189 
1190 /**
1191  *	dmi_memdev_handle - get the DMI handle of a memory slot
1192  *	@slot: slot number
1193  *
1194  *	Return the DMI handle associated with a given memory slot, or %0xFFFF
1195  *      if there is no such slot.
1196  */
1197 u16 dmi_memdev_handle(int slot)
1198 {
1199 	if (dmi_memdev && slot >= 0 && slot < dmi_memdev_nr)
1200 		return dmi_memdev[slot].handle;
1201 
1202 	return 0xffff;	/* Not a valid value */
1203 }
1204 EXPORT_SYMBOL_GPL(dmi_memdev_handle);
1205