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v6.2
   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
  18struct kobject *dmi_kobj;
  19EXPORT_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 */
  26static const char dmi_empty_string[] = "";
  27
  28static u32 dmi_ver __initdata;
  29static u32 dmi_len;
  30static u16 dmi_num;
  31static u8 smbios_entry_point[32];
  32static int smbios_entry_point_size;
  33
  34/* DMI system identification string used during boot */
  35static char dmi_ids_string[128] __initdata;
  36
  37static 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;
  44static int dmi_memdev_nr;
  45
  46static 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
  66static 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 */
  87static 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
 135static phys_addr_t dmi_base;
 136
 137static 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
 155static 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
 166static const char *dmi_ident[DMI_STRING_MAX];
 167static LIST_HEAD(dmi_devices);
 168int dmi_available;
 169EXPORT_SYMBOL_GPL(dmi_available);
 170
 171/*
 172 *	Save a DMI string
 173 */
 174static 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
 190static 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
 218static 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
 256static 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
 274static 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
 293static 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
 308static 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
 335static 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
 357static 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
 384static 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
 402static 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
 414static 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
 421static 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
 455static 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 */
 469static 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
 519static 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
 535static 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 */
 566static int __init dmi_present(const u8 *buf)
 567{
 568	u32 smbios_ver;
 569
 570	/*
 571	 * The size of this structure is 31 bytes, but we also accept value
 572	 * 30 due to a mistake in SMBIOS specification version 2.1.
 573	 */
 574	if (memcmp(buf, "_SM_", 4) == 0 &&
 575	    buf[5] >= 30 && buf[5] <= 32 &&
 576	    dmi_checksum(buf, buf[5])) {
 577		smbios_ver = get_unaligned_be16(buf + 6);
 578		smbios_entry_point_size = buf[5];
 579		memcpy(smbios_entry_point, buf, smbios_entry_point_size);
 580
 581		/* Some BIOS report weird SMBIOS version, fix that up */
 582		switch (smbios_ver) {
 583		case 0x021F:
 584		case 0x0221:
 585			pr_debug("SMBIOS version fixup (2.%d->2.%d)\n",
 586				 smbios_ver & 0xFF, 3);
 587			smbios_ver = 0x0203;
 588			break;
 589		case 0x0233:
 590			pr_debug("SMBIOS version fixup (2.%d->2.%d)\n", 51, 6);
 591			smbios_ver = 0x0206;
 592			break;
 593		}
 594	} else {
 595		smbios_ver = 0;
 596	}
 597
 598	buf += 16;
 599
 600	if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {
 601		if (smbios_ver)
 602			dmi_ver = smbios_ver;
 603		else
 604			dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F);
 605		dmi_ver <<= 8;
 606		dmi_num = get_unaligned_le16(buf + 12);
 607		dmi_len = get_unaligned_le16(buf + 6);
 608		dmi_base = get_unaligned_le32(buf + 8);
 609
 610		if (dmi_walk_early(dmi_decode) == 0) {
 611			if (smbios_ver) {
 612				pr_info("SMBIOS %d.%d present.\n",
 613					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
 614			} else {
 615				smbios_entry_point_size = 15;
 616				memcpy(smbios_entry_point, buf,
 617				       smbios_entry_point_size);
 618				pr_info("Legacy DMI %d.%d present.\n",
 619					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
 620			}
 621			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
 622			pr_info("DMI: %s\n", dmi_ids_string);
 623			return 0;
 624		}
 625	}
 626
 627	return 1;
 628}
 629
 630/*
 631 * Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy
 632 * 32-bit entry point, there is no embedded DMI header (_DMI_) in here.
 633 */
 634static int __init dmi_smbios3_present(const u8 *buf)
 635{
 636	if (memcmp(buf, "_SM3_", 5) == 0 &&
 637	    buf[6] >= 24 && buf[6] <= 32 &&
 638	    dmi_checksum(buf, buf[6])) {
 639		dmi_ver = get_unaligned_be24(buf + 7);
 640		dmi_num = 0;			/* No longer specified */
 641		dmi_len = get_unaligned_le32(buf + 12);
 642		dmi_base = get_unaligned_le64(buf + 16);
 643		smbios_entry_point_size = buf[6];
 644		memcpy(smbios_entry_point, buf, smbios_entry_point_size);
 645
 646		if (dmi_walk_early(dmi_decode) == 0) {
 647			pr_info("SMBIOS %d.%d.%d present.\n",
 648				dmi_ver >> 16, (dmi_ver >> 8) & 0xFF,
 649				dmi_ver & 0xFF);
 650			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
 651			pr_info("DMI: %s\n", dmi_ids_string);
 652			return 0;
 653		}
 654	}
 655	return 1;
 656}
 657
 658static void __init dmi_scan_machine(void)
 659{
 660	char __iomem *p, *q;
 661	char buf[32];
 662
 663	if (efi_enabled(EFI_CONFIG_TABLES)) {
 664		/*
 665		 * According to the DMTF SMBIOS reference spec v3.0.0, it is
 666		 * allowed to define both the 64-bit entry point (smbios3) and
 667		 * the 32-bit entry point (smbios), in which case they should
 668		 * either both point to the same SMBIOS structure table, or the
 669		 * table pointed to by the 64-bit entry point should contain a
 670		 * superset of the table contents pointed to by the 32-bit entry
 671		 * point (section 5.2)
 672		 * This implies that the 64-bit entry point should have
 673		 * precedence if it is defined and supported by the OS. If we
 674		 * have the 64-bit entry point, but fail to decode it, fall
 675		 * back to the legacy one (if available)
 676		 */
 677		if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) {
 678			p = dmi_early_remap(efi.smbios3, 32);
 679			if (p == NULL)
 680				goto error;
 681			memcpy_fromio(buf, p, 32);
 682			dmi_early_unmap(p, 32);
 683
 684			if (!dmi_smbios3_present(buf)) {
 685				dmi_available = 1;
 686				return;
 687			}
 688		}
 689		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
 690			goto error;
 691
 692		/* This is called as a core_initcall() because it isn't
 693		 * needed during early boot.  This also means we can
 694		 * iounmap the space when we're done with it.
 695		 */
 696		p = dmi_early_remap(efi.smbios, 32);
 697		if (p == NULL)
 698			goto error;
 699		memcpy_fromio(buf, p, 32);
 700		dmi_early_unmap(p, 32);
 701
 702		if (!dmi_present(buf)) {
 703			dmi_available = 1;
 704			return;
 705		}
 706	} else if (IS_ENABLED(CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK)) {
 707		p = dmi_early_remap(SMBIOS_ENTRY_POINT_SCAN_START, 0x10000);
 708		if (p == NULL)
 709			goto error;
 710
 711		/*
 712		 * Same logic as above, look for a 64-bit entry point
 713		 * first, and if not found, fall back to 32-bit entry point.
 714		 */
 715		memcpy_fromio(buf, p, 16);
 716		for (q = p + 16; q < p + 0x10000; q += 16) {
 717			memcpy_fromio(buf + 16, q, 16);
 718			if (!dmi_smbios3_present(buf)) {
 719				dmi_available = 1;
 720				dmi_early_unmap(p, 0x10000);
 721				return;
 722			}
 723			memcpy(buf, buf + 16, 16);
 724		}
 725
 726		/*
 727		 * Iterate over all possible DMI header addresses q.
 728		 * Maintain the 32 bytes around q in buf.  On the
 729		 * first iteration, substitute zero for the
 730		 * out-of-range bytes so there is no chance of falsely
 731		 * detecting an SMBIOS header.
 732		 */
 733		memset(buf, 0, 16);
 734		for (q = p; q < p + 0x10000; q += 16) {
 735			memcpy_fromio(buf + 16, q, 16);
 736			if (!dmi_present(buf)) {
 737				dmi_available = 1;
 738				dmi_early_unmap(p, 0x10000);
 739				return;
 740			}
 741			memcpy(buf, buf + 16, 16);
 742		}
 743		dmi_early_unmap(p, 0x10000);
 744	}
 745 error:
 746	pr_info("DMI not present or invalid.\n");
 747}
 748
 749static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
 750			      struct bin_attribute *attr, char *buf,
 751			      loff_t pos, size_t count)
 752{
 753	memcpy(buf, attr->private + pos, count);
 754	return count;
 755}
 756
 757static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0);
 758static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0);
 759
 760static int __init dmi_init(void)
 761{
 762	struct kobject *tables_kobj;
 763	u8 *dmi_table;
 764	int ret = -ENOMEM;
 765
 766	if (!dmi_available)
 767		return 0;
 768
 769	/*
 770	 * Set up dmi directory at /sys/firmware/dmi. This entry should stay
 771	 * even after farther error, as it can be used by other modules like
 772	 * dmi-sysfs.
 773	 */
 774	dmi_kobj = kobject_create_and_add("dmi", firmware_kobj);
 775	if (!dmi_kobj)
 776		goto err;
 777
 778	tables_kobj = kobject_create_and_add("tables", dmi_kobj);
 779	if (!tables_kobj)
 780		goto err;
 781
 782	dmi_table = dmi_remap(dmi_base, dmi_len);
 783	if (!dmi_table)
 784		goto err_tables;
 785
 786	bin_attr_smbios_entry_point.size = smbios_entry_point_size;
 787	bin_attr_smbios_entry_point.private = smbios_entry_point;
 788	ret = sysfs_create_bin_file(tables_kobj, &bin_attr_smbios_entry_point);
 789	if (ret)
 790		goto err_unmap;
 791
 792	bin_attr_DMI.size = dmi_len;
 793	bin_attr_DMI.private = dmi_table;
 794	ret = sysfs_create_bin_file(tables_kobj, &bin_attr_DMI);
 795	if (!ret)
 796		return 0;
 797
 798	sysfs_remove_bin_file(tables_kobj,
 799			      &bin_attr_smbios_entry_point);
 800 err_unmap:
 801	dmi_unmap(dmi_table);
 802 err_tables:
 803	kobject_del(tables_kobj);
 804	kobject_put(tables_kobj);
 805 err:
 806	pr_err("dmi: Firmware registration failed.\n");
 807
 808	return ret;
 809}
 810subsys_initcall(dmi_init);
 811
 812/**
 813 *	dmi_setup - scan and setup DMI system information
 814 *
 815 *	Scan the DMI system information. This setups DMI identifiers
 816 *	(dmi_system_id) for printing it out on task dumps and prepares
 817 *	DIMM entry information (dmi_memdev_info) from the SMBIOS table
 818 *	for using this when reporting memory errors.
 819 */
 820void __init dmi_setup(void)
 821{
 822	dmi_scan_machine();
 823	if (!dmi_available)
 824		return;
 825
 826	dmi_memdev_walk();
 827	dump_stack_set_arch_desc("%s", dmi_ids_string);
 828}
 829
 830/**
 831 *	dmi_matches - check if dmi_system_id structure matches system DMI data
 832 *	@dmi: pointer to the dmi_system_id structure to check
 833 */
 834static bool dmi_matches(const struct dmi_system_id *dmi)
 835{
 836	int i;
 837
 838	for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
 839		int s = dmi->matches[i].slot;
 840		if (s == DMI_NONE)
 841			break;
 842		if (s == DMI_OEM_STRING) {
 843			/* DMI_OEM_STRING must be exact match */
 844			const struct dmi_device *valid;
 845
 846			valid = dmi_find_device(DMI_DEV_TYPE_OEM_STRING,
 847						dmi->matches[i].substr, NULL);
 848			if (valid)
 849				continue;
 850		} else if (dmi_ident[s]) {
 851			if (dmi->matches[i].exact_match) {
 852				if (!strcmp(dmi_ident[s],
 853					    dmi->matches[i].substr))
 854					continue;
 855			} else {
 856				if (strstr(dmi_ident[s],
 857					   dmi->matches[i].substr))
 858					continue;
 859			}
 860		}
 861
 862		/* No match */
 863		return false;
 864	}
 865	return true;
 866}
 867
 868/**
 869 *	dmi_is_end_of_table - check for end-of-table marker
 870 *	@dmi: pointer to the dmi_system_id structure to check
 871 */
 872static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
 873{
 874	return dmi->matches[0].slot == DMI_NONE;
 875}
 876
 877/**
 878 *	dmi_check_system - check system DMI data
 879 *	@list: array of dmi_system_id structures to match against
 880 *		All non-null elements of the list must match
 881 *		their slot's (field index's) data (i.e., each
 882 *		list string must be a substring of the specified
 883 *		DMI slot's string data) to be considered a
 884 *		successful match.
 885 *
 886 *	Walk the blacklist table running matching functions until someone
 887 *	returns non zero or we hit the end. Callback function is called for
 888 *	each successful match. Returns the number of matches.
 889 *
 890 *	dmi_setup must be called before this function is called.
 891 */
 892int dmi_check_system(const struct dmi_system_id *list)
 893{
 894	int count = 0;
 895	const struct dmi_system_id *d;
 896
 897	for (d = list; !dmi_is_end_of_table(d); d++)
 898		if (dmi_matches(d)) {
 899			count++;
 900			if (d->callback && d->callback(d))
 901				break;
 902		}
 903
 904	return count;
 905}
 906EXPORT_SYMBOL(dmi_check_system);
 907
 908/**
 909 *	dmi_first_match - find dmi_system_id structure matching system DMI data
 910 *	@list: array of dmi_system_id structures to match against
 911 *		All non-null elements of the list must match
 912 *		their slot's (field index's) data (i.e., each
 913 *		list string must be a substring of the specified
 914 *		DMI slot's string data) to be considered a
 915 *		successful match.
 916 *
 917 *	Walk the blacklist table until the first match is found.  Return the
 918 *	pointer to the matching entry or NULL if there's no match.
 919 *
 920 *	dmi_setup must be called before this function is called.
 921 */
 922const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
 923{
 924	const struct dmi_system_id *d;
 925
 926	for (d = list; !dmi_is_end_of_table(d); d++)
 927		if (dmi_matches(d))
 928			return d;
 929
 930	return NULL;
 931}
 932EXPORT_SYMBOL(dmi_first_match);
 933
 934/**
 935 *	dmi_get_system_info - return DMI data value
 936 *	@field: data index (see enum dmi_field)
 937 *
 938 *	Returns one DMI data value, can be used to perform
 939 *	complex DMI data checks.
 940 */
 941const char *dmi_get_system_info(int field)
 942{
 943	return dmi_ident[field];
 944}
 945EXPORT_SYMBOL(dmi_get_system_info);
 946
 947/**
 948 * dmi_name_in_serial - Check if string is in the DMI product serial information
 949 * @str: string to check for
 950 */
 951int dmi_name_in_serial(const char *str)
 952{
 953	int f = DMI_PRODUCT_SERIAL;
 954	if (dmi_ident[f] && strstr(dmi_ident[f], str))
 955		return 1;
 956	return 0;
 957}
 958
 959/**
 960 *	dmi_name_in_vendors - Check if string is in the DMI system or board vendor name
 961 *	@str: Case sensitive Name
 962 */
 963int dmi_name_in_vendors(const char *str)
 964{
 965	static int fields[] = { DMI_SYS_VENDOR, DMI_BOARD_VENDOR, DMI_NONE };
 966	int i;
 967	for (i = 0; fields[i] != DMI_NONE; i++) {
 968		int f = fields[i];
 969		if (dmi_ident[f] && strstr(dmi_ident[f], str))
 970			return 1;
 971	}
 972	return 0;
 973}
 974EXPORT_SYMBOL(dmi_name_in_vendors);
 975
 976/**
 977 *	dmi_find_device - find onboard device by type/name
 978 *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
 979 *	@name: device name string or %NULL to match all
 980 *	@from: previous device found in search, or %NULL for new search.
 981 *
 982 *	Iterates through the list of known onboard devices. If a device is
 983 *	found with a matching @type and @name, a pointer to its device
 984 *	structure is returned.  Otherwise, %NULL is returned.
 985 *	A new search is initiated by passing %NULL as the @from argument.
 986 *	If @from is not %NULL, searches continue from next device.
 987 */
 988const struct dmi_device *dmi_find_device(int type, const char *name,
 989				    const struct dmi_device *from)
 990{
 991	const struct list_head *head = from ? &from->list : &dmi_devices;
 992	struct list_head *d;
 993
 994	for (d = head->next; d != &dmi_devices; d = d->next) {
 995		const struct dmi_device *dev =
 996			list_entry(d, struct dmi_device, list);
 997
 998		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
 999		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
1000			return dev;
1001	}
1002
1003	return NULL;
1004}
1005EXPORT_SYMBOL(dmi_find_device);
1006
1007/**
1008 *	dmi_get_date - parse a DMI date
1009 *	@field:	data index (see enum dmi_field)
1010 *	@yearp: optional out parameter for the year
1011 *	@monthp: optional out parameter for the month
1012 *	@dayp: optional out parameter for the day
1013 *
1014 *	The date field is assumed to be in the form resembling
1015 *	[mm[/dd]]/yy[yy] and the result is stored in the out
1016 *	parameters any or all of which can be omitted.
1017 *
1018 *	If the field doesn't exist, all out parameters are set to zero
1019 *	and false is returned.  Otherwise, true is returned with any
1020 *	invalid part of date set to zero.
1021 *
1022 *	On return, year, month and day are guaranteed to be in the
1023 *	range of [0,9999], [0,12] and [0,31] respectively.
1024 */
1025bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
1026{
1027	int year = 0, month = 0, day = 0;
1028	bool exists;
1029	const char *s, *y;
1030	char *e;
1031
1032	s = dmi_get_system_info(field);
1033	exists = s;
1034	if (!exists)
1035		goto out;
1036
1037	/*
1038	 * Determine year first.  We assume the date string resembles
1039	 * mm/dd/yy[yy] but the original code extracted only the year
1040	 * from the end.  Keep the behavior in the spirit of no
1041	 * surprises.
1042	 */
1043	y = strrchr(s, '/');
1044	if (!y)
1045		goto out;
1046
1047	y++;
1048	year = simple_strtoul(y, &e, 10);
1049	if (y != e && year < 100) {	/* 2-digit year */
1050		year += 1900;
1051		if (year < 1996)	/* no dates < spec 1.0 */
1052			year += 100;
1053	}
1054	if (year > 9999)		/* year should fit in %04d */
1055		year = 0;
1056
1057	/* parse the mm and dd */
1058	month = simple_strtoul(s, &e, 10);
1059	if (s == e || *e != '/' || !month || month > 12) {
1060		month = 0;
1061		goto out;
1062	}
1063
1064	s = e + 1;
1065	day = simple_strtoul(s, &e, 10);
1066	if (s == y || s == e || *e != '/' || day > 31)
1067		day = 0;
1068out:
1069	if (yearp)
1070		*yearp = year;
1071	if (monthp)
1072		*monthp = month;
1073	if (dayp)
1074		*dayp = day;
1075	return exists;
1076}
1077EXPORT_SYMBOL(dmi_get_date);
1078
1079/**
1080 *	dmi_get_bios_year - get a year out of DMI_BIOS_DATE field
1081 *
1082 *	Returns year on success, -ENXIO if DMI is not selected,
1083 *	or a different negative error code if DMI field is not present
1084 *	or not parseable.
1085 */
1086int dmi_get_bios_year(void)
1087{
1088	bool exists;
1089	int year;
1090
1091	exists = dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
1092	if (!exists)
1093		return -ENODATA;
1094
1095	return year ? year : -ERANGE;
1096}
1097EXPORT_SYMBOL(dmi_get_bios_year);
1098
1099/**
1100 *	dmi_walk - Walk the DMI table and get called back for every record
1101 *	@decode: Callback function
1102 *	@private_data: Private data to be passed to the callback function
1103 *
1104 *	Returns 0 on success, -ENXIO if DMI is not selected or not present,
1105 *	or a different negative error code if DMI walking fails.
1106 */
1107int dmi_walk(void (*decode)(const struct dmi_header *, void *),
1108	     void *private_data)
1109{
1110	u8 *buf;
1111
1112	if (!dmi_available)
1113		return -ENXIO;
1114
1115	buf = dmi_remap(dmi_base, dmi_len);
1116	if (buf == NULL)
1117		return -ENOMEM;
1118
1119	dmi_decode_table(buf, decode, private_data);
1120
1121	dmi_unmap(buf);
1122	return 0;
1123}
1124EXPORT_SYMBOL_GPL(dmi_walk);
1125
1126/**
1127 * dmi_match - compare a string to the dmi field (if exists)
1128 * @f: DMI field identifier
1129 * @str: string to compare the DMI field to
1130 *
1131 * Returns true if the requested field equals to the str (including NULL).
1132 */
1133bool dmi_match(enum dmi_field f, const char *str)
1134{
1135	const char *info = dmi_get_system_info(f);
1136
1137	if (info == NULL || str == NULL)
1138		return info == str;
1139
1140	return !strcmp(info, str);
1141}
1142EXPORT_SYMBOL_GPL(dmi_match);
1143
1144void dmi_memdev_name(u16 handle, const char **bank, const char **device)
1145{
1146	int n;
1147
1148	if (dmi_memdev == NULL)
1149		return;
1150
1151	for (n = 0; n < dmi_memdev_nr; n++) {
1152		if (handle == dmi_memdev[n].handle) {
1153			*bank = dmi_memdev[n].bank;
1154			*device = dmi_memdev[n].device;
1155			break;
1156		}
1157	}
1158}
1159EXPORT_SYMBOL_GPL(dmi_memdev_name);
1160
1161u64 dmi_memdev_size(u16 handle)
1162{
1163	int n;
1164
1165	if (dmi_memdev) {
1166		for (n = 0; n < dmi_memdev_nr; n++) {
1167			if (handle == dmi_memdev[n].handle)
1168				return dmi_memdev[n].size;
1169		}
1170	}
1171	return ~0ull;
1172}
1173EXPORT_SYMBOL_GPL(dmi_memdev_size);
1174
1175/**
1176 * dmi_memdev_type - get the memory type
1177 * @handle: DMI structure handle
1178 *
1179 * Return the DMI memory type of the module in the slot associated with the
1180 * given DMI handle, or 0x0 if no such DMI handle exists.
1181 */
1182u8 dmi_memdev_type(u16 handle)
1183{
1184	int n;
1185
1186	if (dmi_memdev) {
1187		for (n = 0; n < dmi_memdev_nr; n++) {
1188			if (handle == dmi_memdev[n].handle)
1189				return dmi_memdev[n].type;
1190		}
1191	}
1192	return 0x0;	/* Not a valid value */
1193}
1194EXPORT_SYMBOL_GPL(dmi_memdev_type);
1195
1196/**
1197 *	dmi_memdev_handle - get the DMI handle of a memory slot
1198 *	@slot: slot number
1199 *
1200 *	Return the DMI handle associated with a given memory slot, or %0xFFFF
1201 *      if there is no such slot.
1202 */
1203u16 dmi_memdev_handle(int slot)
1204{
1205	if (dmi_memdev && slot >= 0 && slot < dmi_memdev_nr)
1206		return dmi_memdev[slot].handle;
1207
1208	return 0xffff;	/* Not a valid value */
1209}
1210EXPORT_SYMBOL_GPL(dmi_memdev_handle);
v4.17
 
   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#include <asm/unaligned.h>
  12
 
 
 
 
  13struct kobject *dmi_kobj;
  14EXPORT_SYMBOL_GPL(dmi_kobj);
  15
  16/*
  17 * DMI stands for "Desktop Management Interface".  It is part
  18 * of and an antecedent to, SMBIOS, which stands for System
  19 * Management BIOS.  See further: http://www.dmtf.org/standards
  20 */
  21static const char dmi_empty_string[] = "";
  22
  23static u32 dmi_ver __initdata;
  24static u32 dmi_len;
  25static u16 dmi_num;
  26static u8 smbios_entry_point[32];
  27static int smbios_entry_point_size;
  28
  29/* DMI system identification string used during boot */
  30static char dmi_ids_string[128] __initdata;
  31
  32static struct dmi_memdev_info {
  33	const char *device;
  34	const char *bank;
  35	u64 size;		/* bytes */
  36	u16 handle;
 
  37} *dmi_memdev;
  38static int dmi_memdev_nr;
  39
  40static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
  41{
  42	const u8 *bp = ((u8 *) dm) + dm->length;
  43	const u8 *nsp;
  44
  45	if (s) {
  46		while (--s > 0 && *bp)
  47			bp += strlen(bp) + 1;
  48
  49		/* Strings containing only spaces are considered empty */
  50		nsp = bp;
  51		while (*nsp == ' ')
  52			nsp++;
  53		if (*nsp != '\0')
  54			return bp;
  55	}
  56
  57	return dmi_empty_string;
  58}
  59
  60static const char * __init dmi_string(const struct dmi_header *dm, u8 s)
  61{
  62	const char *bp = dmi_string_nosave(dm, s);
  63	char *str;
  64	size_t len;
  65
  66	if (bp == dmi_empty_string)
  67		return dmi_empty_string;
  68
  69	len = strlen(bp) + 1;
  70	str = dmi_alloc(len);
  71	if (str != NULL)
  72		strcpy(str, bp);
  73
  74	return str;
  75}
  76
  77/*
  78 *	We have to be cautious here. We have seen BIOSes with DMI pointers
  79 *	pointing to completely the wrong place for example
  80 */
  81static void dmi_decode_table(u8 *buf,
  82			     void (*decode)(const struct dmi_header *, void *),
  83			     void *private_data)
  84{
  85	u8 *data = buf;
  86	int i = 0;
  87
  88	/*
  89	 * Stop when we have seen all the items the table claimed to have
  90	 * (SMBIOS < 3.0 only) OR we reach an end-of-table marker (SMBIOS
  91	 * >= 3.0 only) OR we run off the end of the table (should never
  92	 * happen but sometimes does on bogus implementations.)
  93	 */
  94	while ((!dmi_num || i < dmi_num) &&
  95	       (data - buf + sizeof(struct dmi_header)) <= dmi_len) {
  96		const struct dmi_header *dm = (const struct dmi_header *)data;
  97
  98		/*
  99		 *  We want to know the total length (formatted area and
 100		 *  strings) before decoding to make sure we won't run off the
 101		 *  table in dmi_decode or dmi_string
 102		 */
 103		data += dm->length;
 104		while ((data - buf < dmi_len - 1) && (data[0] || data[1]))
 105			data++;
 106		if (data - buf < dmi_len - 1)
 107			decode(dm, private_data);
 108
 109		data += 2;
 110		i++;
 111
 112		/*
 113		 * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
 114		 * For tables behind a 64-bit entry point, we have no item
 115		 * count and no exact table length, so stop on end-of-table
 116		 * marker. For tables behind a 32-bit entry point, we have
 117		 * seen OEM structures behind the end-of-table marker on
 118		 * some systems, so don't trust it.
 119		 */
 120		if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE)
 121			break;
 122	}
 123
 124	/* Trim DMI table length if needed */
 125	if (dmi_len > data - buf)
 126		dmi_len = data - buf;
 127}
 128
 129static phys_addr_t dmi_base;
 130
 131static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
 132		void *))
 133{
 134	u8 *buf;
 135	u32 orig_dmi_len = dmi_len;
 136
 137	buf = dmi_early_remap(dmi_base, orig_dmi_len);
 138	if (buf == NULL)
 139		return -ENOMEM;
 140
 141	dmi_decode_table(buf, decode, NULL);
 142
 143	add_device_randomness(buf, dmi_len);
 144
 145	dmi_early_unmap(buf, orig_dmi_len);
 146	return 0;
 147}
 148
 149static int __init dmi_checksum(const u8 *buf, u8 len)
 150{
 151	u8 sum = 0;
 152	int a;
 153
 154	for (a = 0; a < len; a++)
 155		sum += buf[a];
 156
 157	return sum == 0;
 158}
 159
 160static const char *dmi_ident[DMI_STRING_MAX];
 161static LIST_HEAD(dmi_devices);
 162int dmi_available;
 
 163
 164/*
 165 *	Save a DMI string
 166 */
 167static void __init dmi_save_ident(const struct dmi_header *dm, int slot,
 168		int string)
 169{
 170	const char *d = (const char *) dm;
 171	const char *p;
 172
 173	if (dmi_ident[slot] || dm->length <= string)
 174		return;
 175
 176	p = dmi_string(dm, d[string]);
 177	if (p == NULL)
 178		return;
 179
 180	dmi_ident[slot] = p;
 181}
 182
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 183static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
 184		int index)
 185{
 186	const u8 *d;
 187	char *s;
 188	int is_ff = 1, is_00 = 1, i;
 189
 190	if (dmi_ident[slot] || dm->length < index + 16)
 191		return;
 192
 193	d = (u8 *) dm + index;
 194	for (i = 0; i < 16 && (is_ff || is_00); i++) {
 195		if (d[i] != 0x00)
 196			is_00 = 0;
 197		if (d[i] != 0xFF)
 198			is_ff = 0;
 199	}
 200
 201	if (is_ff || is_00)
 202		return;
 203
 204	s = dmi_alloc(16*2+4+1);
 205	if (!s)
 206		return;
 207
 208	/*
 209	 * As of version 2.6 of the SMBIOS specification, the first 3 fields of
 210	 * the UUID are supposed to be little-endian encoded.  The specification
 211	 * says that this is the defacto standard.
 212	 */
 213	if (dmi_ver >= 0x020600)
 214		sprintf(s, "%pUl", d);
 215	else
 216		sprintf(s, "%pUb", d);
 217
 218	dmi_ident[slot] = s;
 219}
 220
 221static void __init dmi_save_type(const struct dmi_header *dm, int slot,
 222		int index)
 223{
 224	const u8 *d;
 225	char *s;
 226
 227	if (dmi_ident[slot] || dm->length <= index)
 228		return;
 229
 230	s = dmi_alloc(4);
 231	if (!s)
 232		return;
 233
 234	d = (u8 *) dm + index;
 235	sprintf(s, "%u", *d & 0x7F);
 236	dmi_ident[slot] = s;
 237}
 238
 239static void __init dmi_save_one_device(int type, const char *name)
 240{
 241	struct dmi_device *dev;
 242
 243	/* No duplicate device */
 244	if (dmi_find_device(type, name, NULL))
 245		return;
 246
 247	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
 248	if (!dev)
 249		return;
 250
 251	dev->type = type;
 252	strcpy((char *)(dev + 1), name);
 253	dev->name = (char *)(dev + 1);
 254	dev->device_data = NULL;
 255	list_add(&dev->list, &dmi_devices);
 256}
 257
 258static void __init dmi_save_devices(const struct dmi_header *dm)
 259{
 260	int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
 261
 262	for (i = 0; i < count; i++) {
 263		const char *d = (char *)(dm + 1) + (i * 2);
 264
 265		/* Skip disabled device */
 266		if ((*d & 0x80) == 0)
 267			continue;
 268
 269		dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
 270	}
 271}
 272
 273static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
 274{
 275	int i, count;
 276	struct dmi_device *dev;
 277
 278	if (dm->length < 0x05)
 279		return;
 280
 281	count = *(u8 *)(dm + 1);
 282	for (i = 1; i <= count; i++) {
 283		const char *devname = dmi_string(dm, i);
 284
 285		if (devname == dmi_empty_string)
 286			continue;
 287
 288		dev = dmi_alloc(sizeof(*dev));
 289		if (!dev)
 290			break;
 291
 292		dev->type = DMI_DEV_TYPE_OEM_STRING;
 293		dev->name = devname;
 294		dev->device_data = NULL;
 295
 296		list_add(&dev->list, &dmi_devices);
 297	}
 298}
 299
 300static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
 301{
 302	struct dmi_device *dev;
 303	void *data;
 304
 305	data = dmi_alloc(dm->length);
 306	if (data == NULL)
 307		return;
 308
 309	memcpy(data, dm, dm->length);
 310
 311	dev = dmi_alloc(sizeof(*dev));
 312	if (!dev)
 313		return;
 314
 315	dev->type = DMI_DEV_TYPE_IPMI;
 316	dev->name = "IPMI controller";
 317	dev->device_data = data;
 318
 319	list_add_tail(&dev->list, &dmi_devices);
 320}
 321
 322static void __init dmi_save_dev_pciaddr(int instance, int segment, int bus,
 323					int devfn, const char *name, int type)
 324{
 325	struct dmi_dev_onboard *dev;
 326
 327	/* Ignore invalid values */
 328	if (type == DMI_DEV_TYPE_DEV_SLOT &&
 329	    segment == 0xFFFF && bus == 0xFF && devfn == 0xFF)
 330		return;
 331
 332	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
 333	if (!dev)
 334		return;
 335
 336	dev->instance = instance;
 337	dev->segment = segment;
 338	dev->bus = bus;
 339	dev->devfn = devfn;
 340
 341	strcpy((char *)&dev[1], name);
 342	dev->dev.type = type;
 343	dev->dev.name = (char *)&dev[1];
 344	dev->dev.device_data = dev;
 345
 346	list_add(&dev->dev.list, &dmi_devices);
 347}
 348
 349static void __init dmi_save_extended_devices(const struct dmi_header *dm)
 350{
 351	const char *name;
 352	const u8 *d = (u8 *)dm;
 353
 354	if (dm->length < 0x0B)
 355		return;
 356
 357	/* Skip disabled device */
 358	if ((d[0x5] & 0x80) == 0)
 359		return;
 360
 361	name = dmi_string_nosave(dm, d[0x4]);
 362	dmi_save_dev_pciaddr(d[0x6], *(u16 *)(d + 0x7), d[0x9], d[0xA], name,
 363			     DMI_DEV_TYPE_DEV_ONBOARD);
 364	dmi_save_one_device(d[0x5] & 0x7f, name);
 365}
 366
 367static void __init dmi_save_system_slot(const struct dmi_header *dm)
 368{
 369	const u8 *d = (u8 *)dm;
 370
 371	/* Need SMBIOS 2.6+ structure */
 372	if (dm->length < 0x11)
 373		return;
 374	dmi_save_dev_pciaddr(*(u16 *)(d + 0x9), *(u16 *)(d + 0xD), d[0xF],
 375			     d[0x10], dmi_string_nosave(dm, d[0x4]),
 376			     DMI_DEV_TYPE_DEV_SLOT);
 377}
 378
 379static void __init count_mem_devices(const struct dmi_header *dm, void *v)
 380{
 381	if (dm->type != DMI_ENTRY_MEM_DEVICE)
 382		return;
 383	dmi_memdev_nr++;
 384}
 385
 386static void __init save_mem_devices(const struct dmi_header *dm, void *v)
 387{
 388	const char *d = (const char *)dm;
 389	static int nr;
 390	u64 bytes;
 391	u16 size;
 392
 393	if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x12)
 394		return;
 395	if (nr >= dmi_memdev_nr) {
 396		pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
 397		return;
 398	}
 399	dmi_memdev[nr].handle = get_unaligned(&dm->handle);
 400	dmi_memdev[nr].device = dmi_string(dm, d[0x10]);
 401	dmi_memdev[nr].bank = dmi_string(dm, d[0x11]);
 
 402
 403	size = get_unaligned((u16 *)&d[0xC]);
 404	if (size == 0)
 405		bytes = 0;
 406	else if (size == 0xffff)
 407		bytes = ~0ull;
 408	else if (size & 0x8000)
 409		bytes = (u64)(size & 0x7fff) << 10;
 410	else if (size != 0x7fff)
 411		bytes = (u64)size << 20;
 412	else
 413		bytes = (u64)get_unaligned((u32 *)&d[0x1C]) << 20;
 414
 415	dmi_memdev[nr].size = bytes;
 416	nr++;
 417}
 418
 419void __init dmi_memdev_walk(void)
 420{
 421	if (!dmi_available)
 422		return;
 423
 424	if (dmi_walk_early(count_mem_devices) == 0 && dmi_memdev_nr) {
 425		dmi_memdev = dmi_alloc(sizeof(*dmi_memdev) * dmi_memdev_nr);
 426		if (dmi_memdev)
 427			dmi_walk_early(save_mem_devices);
 428	}
 429}
 430
 431/*
 432 *	Process a DMI table entry. Right now all we care about are the BIOS
 433 *	and machine entries. For 2.5 we should pull the smbus controller info
 434 *	out of here.
 435 */
 436static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
 437{
 438	switch (dm->type) {
 439	case 0:		/* BIOS Information */
 440		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
 441		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
 442		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
 
 
 443		break;
 444	case 1:		/* System Information */
 445		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
 446		dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
 447		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
 448		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
 449		dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
 
 450		dmi_save_ident(dm, DMI_PRODUCT_FAMILY, 26);
 451		break;
 452	case 2:		/* Base Board Information */
 453		dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
 454		dmi_save_ident(dm, DMI_BOARD_NAME, 5);
 455		dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
 456		dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
 457		dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
 458		break;
 459	case 3:		/* Chassis Information */
 460		dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
 461		dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
 462		dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
 463		dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
 464		dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
 465		break;
 466	case 9:		/* System Slots */
 467		dmi_save_system_slot(dm);
 468		break;
 469	case 10:	/* Onboard Devices Information */
 470		dmi_save_devices(dm);
 471		break;
 472	case 11:	/* OEM Strings */
 473		dmi_save_oem_strings_devices(dm);
 474		break;
 475	case 38:	/* IPMI Device Information */
 476		dmi_save_ipmi_device(dm);
 477		break;
 478	case 41:	/* Onboard Devices Extended Information */
 479		dmi_save_extended_devices(dm);
 480	}
 481}
 482
 483static int __init print_filtered(char *buf, size_t len, const char *info)
 484{
 485	int c = 0;
 486	const char *p;
 487
 488	if (!info)
 489		return c;
 490
 491	for (p = info; *p; p++)
 492		if (isprint(*p))
 493			c += scnprintf(buf + c, len - c, "%c", *p);
 494		else
 495			c += scnprintf(buf + c, len - c, "\\x%02x", *p & 0xff);
 496	return c;
 497}
 498
 499static void __init dmi_format_ids(char *buf, size_t len)
 500{
 501	int c = 0;
 502	const char *board;	/* Board Name is optional */
 503
 504	c += print_filtered(buf + c, len - c,
 505			    dmi_get_system_info(DMI_SYS_VENDOR));
 506	c += scnprintf(buf + c, len - c, " ");
 507	c += print_filtered(buf + c, len - c,
 508			    dmi_get_system_info(DMI_PRODUCT_NAME));
 509
 510	board = dmi_get_system_info(DMI_BOARD_NAME);
 511	if (board) {
 512		c += scnprintf(buf + c, len - c, "/");
 513		c += print_filtered(buf + c, len - c, board);
 514	}
 515	c += scnprintf(buf + c, len - c, ", BIOS ");
 516	c += print_filtered(buf + c, len - c,
 517			    dmi_get_system_info(DMI_BIOS_VERSION));
 518	c += scnprintf(buf + c, len - c, " ");
 519	c += print_filtered(buf + c, len - c,
 520			    dmi_get_system_info(DMI_BIOS_DATE));
 521}
 522
 523/*
 524 * Check for DMI/SMBIOS headers in the system firmware image.  Any
 525 * SMBIOS header must start 16 bytes before the DMI header, so take a
 526 * 32 byte buffer and check for DMI at offset 16 and SMBIOS at offset
 527 * 0.  If the DMI header is present, set dmi_ver accordingly (SMBIOS
 528 * takes precedence) and return 0.  Otherwise return 1.
 529 */
 530static int __init dmi_present(const u8 *buf)
 531{
 532	u32 smbios_ver;
 533
 
 
 
 
 534	if (memcmp(buf, "_SM_", 4) == 0 &&
 535	    buf[5] < 32 && dmi_checksum(buf, buf[5])) {
 
 536		smbios_ver = get_unaligned_be16(buf + 6);
 537		smbios_entry_point_size = buf[5];
 538		memcpy(smbios_entry_point, buf, smbios_entry_point_size);
 539
 540		/* Some BIOS report weird SMBIOS version, fix that up */
 541		switch (smbios_ver) {
 542		case 0x021F:
 543		case 0x0221:
 544			pr_debug("SMBIOS version fixup (2.%d->2.%d)\n",
 545				 smbios_ver & 0xFF, 3);
 546			smbios_ver = 0x0203;
 547			break;
 548		case 0x0233:
 549			pr_debug("SMBIOS version fixup (2.%d->2.%d)\n", 51, 6);
 550			smbios_ver = 0x0206;
 551			break;
 552		}
 553	} else {
 554		smbios_ver = 0;
 555	}
 556
 557	buf += 16;
 558
 559	if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {
 560		if (smbios_ver)
 561			dmi_ver = smbios_ver;
 562		else
 563			dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F);
 564		dmi_ver <<= 8;
 565		dmi_num = get_unaligned_le16(buf + 12);
 566		dmi_len = get_unaligned_le16(buf + 6);
 567		dmi_base = get_unaligned_le32(buf + 8);
 568
 569		if (dmi_walk_early(dmi_decode) == 0) {
 570			if (smbios_ver) {
 571				pr_info("SMBIOS %d.%d present.\n",
 572					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
 573			} else {
 574				smbios_entry_point_size = 15;
 575				memcpy(smbios_entry_point, buf,
 576				       smbios_entry_point_size);
 577				pr_info("Legacy DMI %d.%d present.\n",
 578					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
 579			}
 580			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
 581			pr_info("DMI: %s\n", dmi_ids_string);
 582			return 0;
 583		}
 584	}
 585
 586	return 1;
 587}
 588
 589/*
 590 * Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy
 591 * 32-bit entry point, there is no embedded DMI header (_DMI_) in here.
 592 */
 593static int __init dmi_smbios3_present(const u8 *buf)
 594{
 595	if (memcmp(buf, "_SM3_", 5) == 0 &&
 596	    buf[6] < 32 && dmi_checksum(buf, buf[6])) {
 597		dmi_ver = get_unaligned_be32(buf + 6) & 0xFFFFFF;
 
 598		dmi_num = 0;			/* No longer specified */
 599		dmi_len = get_unaligned_le32(buf + 12);
 600		dmi_base = get_unaligned_le64(buf + 16);
 601		smbios_entry_point_size = buf[6];
 602		memcpy(smbios_entry_point, buf, smbios_entry_point_size);
 603
 604		if (dmi_walk_early(dmi_decode) == 0) {
 605			pr_info("SMBIOS %d.%d.%d present.\n",
 606				dmi_ver >> 16, (dmi_ver >> 8) & 0xFF,
 607				dmi_ver & 0xFF);
 608			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
 609			pr_info("DMI: %s\n", dmi_ids_string);
 610			return 0;
 611		}
 612	}
 613	return 1;
 614}
 615
 616void __init dmi_scan_machine(void)
 617{
 618	char __iomem *p, *q;
 619	char buf[32];
 620
 621	if (efi_enabled(EFI_CONFIG_TABLES)) {
 622		/*
 623		 * According to the DMTF SMBIOS reference spec v3.0.0, it is
 624		 * allowed to define both the 64-bit entry point (smbios3) and
 625		 * the 32-bit entry point (smbios), in which case they should
 626		 * either both point to the same SMBIOS structure table, or the
 627		 * table pointed to by the 64-bit entry point should contain a
 628		 * superset of the table contents pointed to by the 32-bit entry
 629		 * point (section 5.2)
 630		 * This implies that the 64-bit entry point should have
 631		 * precedence if it is defined and supported by the OS. If we
 632		 * have the 64-bit entry point, but fail to decode it, fall
 633		 * back to the legacy one (if available)
 634		 */
 635		if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) {
 636			p = dmi_early_remap(efi.smbios3, 32);
 637			if (p == NULL)
 638				goto error;
 639			memcpy_fromio(buf, p, 32);
 640			dmi_early_unmap(p, 32);
 641
 642			if (!dmi_smbios3_present(buf)) {
 643				dmi_available = 1;
 644				return;
 645			}
 646		}
 647		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
 648			goto error;
 649
 650		/* This is called as a core_initcall() because it isn't
 651		 * needed during early boot.  This also means we can
 652		 * iounmap the space when we're done with it.
 653		 */
 654		p = dmi_early_remap(efi.smbios, 32);
 655		if (p == NULL)
 656			goto error;
 657		memcpy_fromio(buf, p, 32);
 658		dmi_early_unmap(p, 32);
 659
 660		if (!dmi_present(buf)) {
 661			dmi_available = 1;
 662			return;
 663		}
 664	} else if (IS_ENABLED(CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK)) {
 665		p = dmi_early_remap(0xF0000, 0x10000);
 666		if (p == NULL)
 667			goto error;
 668
 669		/*
 670		 * Same logic as above, look for a 64-bit entry point
 671		 * first, and if not found, fall back to 32-bit entry point.
 672		 */
 673		memcpy_fromio(buf, p, 16);
 674		for (q = p + 16; q < p + 0x10000; q += 16) {
 675			memcpy_fromio(buf + 16, q, 16);
 676			if (!dmi_smbios3_present(buf)) {
 677				dmi_available = 1;
 678				dmi_early_unmap(p, 0x10000);
 679				return;
 680			}
 681			memcpy(buf, buf + 16, 16);
 682		}
 683
 684		/*
 685		 * Iterate over all possible DMI header addresses q.
 686		 * Maintain the 32 bytes around q in buf.  On the
 687		 * first iteration, substitute zero for the
 688		 * out-of-range bytes so there is no chance of falsely
 689		 * detecting an SMBIOS header.
 690		 */
 691		memset(buf, 0, 16);
 692		for (q = p; q < p + 0x10000; q += 16) {
 693			memcpy_fromio(buf + 16, q, 16);
 694			if (!dmi_present(buf)) {
 695				dmi_available = 1;
 696				dmi_early_unmap(p, 0x10000);
 697				return;
 698			}
 699			memcpy(buf, buf + 16, 16);
 700		}
 701		dmi_early_unmap(p, 0x10000);
 702	}
 703 error:
 704	pr_info("DMI not present or invalid.\n");
 705}
 706
 707static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
 708			      struct bin_attribute *attr, char *buf,
 709			      loff_t pos, size_t count)
 710{
 711	memcpy(buf, attr->private + pos, count);
 712	return count;
 713}
 714
 715static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0);
 716static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0);
 717
 718static int __init dmi_init(void)
 719{
 720	struct kobject *tables_kobj;
 721	u8 *dmi_table;
 722	int ret = -ENOMEM;
 723
 724	if (!dmi_available)
 725		return 0;
 726
 727	/*
 728	 * Set up dmi directory at /sys/firmware/dmi. This entry should stay
 729	 * even after farther error, as it can be used by other modules like
 730	 * dmi-sysfs.
 731	 */
 732	dmi_kobj = kobject_create_and_add("dmi", firmware_kobj);
 733	if (!dmi_kobj)
 734		goto err;
 735
 736	tables_kobj = kobject_create_and_add("tables", dmi_kobj);
 737	if (!tables_kobj)
 738		goto err;
 739
 740	dmi_table = dmi_remap(dmi_base, dmi_len);
 741	if (!dmi_table)
 742		goto err_tables;
 743
 744	bin_attr_smbios_entry_point.size = smbios_entry_point_size;
 745	bin_attr_smbios_entry_point.private = smbios_entry_point;
 746	ret = sysfs_create_bin_file(tables_kobj, &bin_attr_smbios_entry_point);
 747	if (ret)
 748		goto err_unmap;
 749
 750	bin_attr_DMI.size = dmi_len;
 751	bin_attr_DMI.private = dmi_table;
 752	ret = sysfs_create_bin_file(tables_kobj, &bin_attr_DMI);
 753	if (!ret)
 754		return 0;
 755
 756	sysfs_remove_bin_file(tables_kobj,
 757			      &bin_attr_smbios_entry_point);
 758 err_unmap:
 759	dmi_unmap(dmi_table);
 760 err_tables:
 761	kobject_del(tables_kobj);
 762	kobject_put(tables_kobj);
 763 err:
 764	pr_err("dmi: Firmware registration failed.\n");
 765
 766	return ret;
 767}
 768subsys_initcall(dmi_init);
 769
 770/**
 771 * dmi_set_dump_stack_arch_desc - set arch description for dump_stack()
 772 *
 773 * Invoke dump_stack_set_arch_desc() with DMI system information so that
 774 * DMI identifiers are printed out on task dumps.  Arch boot code should
 775 * call this function after dmi_scan_machine() if it wants to print out DMI
 776 * identifiers on task dumps.
 777 */
 778void __init dmi_set_dump_stack_arch_desc(void)
 779{
 
 
 
 
 
 780	dump_stack_set_arch_desc("%s", dmi_ids_string);
 781}
 782
 783/**
 784 *	dmi_matches - check if dmi_system_id structure matches system DMI data
 785 *	@dmi: pointer to the dmi_system_id structure to check
 786 */
 787static bool dmi_matches(const struct dmi_system_id *dmi)
 788{
 789	int i;
 790
 791	for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
 792		int s = dmi->matches[i].slot;
 793		if (s == DMI_NONE)
 794			break;
 795		if (s == DMI_OEM_STRING) {
 796			/* DMI_OEM_STRING must be exact match */
 797			const struct dmi_device *valid;
 798
 799			valid = dmi_find_device(DMI_DEV_TYPE_OEM_STRING,
 800						dmi->matches[i].substr, NULL);
 801			if (valid)
 802				continue;
 803		} else if (dmi_ident[s]) {
 804			if (dmi->matches[i].exact_match) {
 805				if (!strcmp(dmi_ident[s],
 806					    dmi->matches[i].substr))
 807					continue;
 808			} else {
 809				if (strstr(dmi_ident[s],
 810					   dmi->matches[i].substr))
 811					continue;
 812			}
 813		}
 814
 815		/* No match */
 816		return false;
 817	}
 818	return true;
 819}
 820
 821/**
 822 *	dmi_is_end_of_table - check for end-of-table marker
 823 *	@dmi: pointer to the dmi_system_id structure to check
 824 */
 825static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
 826{
 827	return dmi->matches[0].slot == DMI_NONE;
 828}
 829
 830/**
 831 *	dmi_check_system - check system DMI data
 832 *	@list: array of dmi_system_id structures to match against
 833 *		All non-null elements of the list must match
 834 *		their slot's (field index's) data (i.e., each
 835 *		list string must be a substring of the specified
 836 *		DMI slot's string data) to be considered a
 837 *		successful match.
 838 *
 839 *	Walk the blacklist table running matching functions until someone
 840 *	returns non zero or we hit the end. Callback function is called for
 841 *	each successful match. Returns the number of matches.
 842 *
 843 *	dmi_scan_machine must be called before this function is called.
 844 */
 845int dmi_check_system(const struct dmi_system_id *list)
 846{
 847	int count = 0;
 848	const struct dmi_system_id *d;
 849
 850	for (d = list; !dmi_is_end_of_table(d); d++)
 851		if (dmi_matches(d)) {
 852			count++;
 853			if (d->callback && d->callback(d))
 854				break;
 855		}
 856
 857	return count;
 858}
 859EXPORT_SYMBOL(dmi_check_system);
 860
 861/**
 862 *	dmi_first_match - find dmi_system_id structure matching system DMI data
 863 *	@list: array of dmi_system_id structures to match against
 864 *		All non-null elements of the list must match
 865 *		their slot's (field index's) data (i.e., each
 866 *		list string must be a substring of the specified
 867 *		DMI slot's string data) to be considered a
 868 *		successful match.
 869 *
 870 *	Walk the blacklist table until the first match is found.  Return the
 871 *	pointer to the matching entry or NULL if there's no match.
 872 *
 873 *	dmi_scan_machine must be called before this function is called.
 874 */
 875const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
 876{
 877	const struct dmi_system_id *d;
 878
 879	for (d = list; !dmi_is_end_of_table(d); d++)
 880		if (dmi_matches(d))
 881			return d;
 882
 883	return NULL;
 884}
 885EXPORT_SYMBOL(dmi_first_match);
 886
 887/**
 888 *	dmi_get_system_info - return DMI data value
 889 *	@field: data index (see enum dmi_field)
 890 *
 891 *	Returns one DMI data value, can be used to perform
 892 *	complex DMI data checks.
 893 */
 894const char *dmi_get_system_info(int field)
 895{
 896	return dmi_ident[field];
 897}
 898EXPORT_SYMBOL(dmi_get_system_info);
 899
 900/**
 901 * dmi_name_in_serial - Check if string is in the DMI product serial information
 902 * @str: string to check for
 903 */
 904int dmi_name_in_serial(const char *str)
 905{
 906	int f = DMI_PRODUCT_SERIAL;
 907	if (dmi_ident[f] && strstr(dmi_ident[f], str))
 908		return 1;
 909	return 0;
 910}
 911
 912/**
 913 *	dmi_name_in_vendors - Check if string is in the DMI system or board vendor name
 914 *	@str: Case sensitive Name
 915 */
 916int dmi_name_in_vendors(const char *str)
 917{
 918	static int fields[] = { DMI_SYS_VENDOR, DMI_BOARD_VENDOR, DMI_NONE };
 919	int i;
 920	for (i = 0; fields[i] != DMI_NONE; i++) {
 921		int f = fields[i];
 922		if (dmi_ident[f] && strstr(dmi_ident[f], str))
 923			return 1;
 924	}
 925	return 0;
 926}
 927EXPORT_SYMBOL(dmi_name_in_vendors);
 928
 929/**
 930 *	dmi_find_device - find onboard device by type/name
 931 *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
 932 *	@name: device name string or %NULL to match all
 933 *	@from: previous device found in search, or %NULL for new search.
 934 *
 935 *	Iterates through the list of known onboard devices. If a device is
 936 *	found with a matching @type and @name, a pointer to its device
 937 *	structure is returned.  Otherwise, %NULL is returned.
 938 *	A new search is initiated by passing %NULL as the @from argument.
 939 *	If @from is not %NULL, searches continue from next device.
 940 */
 941const struct dmi_device *dmi_find_device(int type, const char *name,
 942				    const struct dmi_device *from)
 943{
 944	const struct list_head *head = from ? &from->list : &dmi_devices;
 945	struct list_head *d;
 946
 947	for (d = head->next; d != &dmi_devices; d = d->next) {
 948		const struct dmi_device *dev =
 949			list_entry(d, struct dmi_device, list);
 950
 951		if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
 952		    ((name == NULL) || (strcmp(dev->name, name) == 0)))
 953			return dev;
 954	}
 955
 956	return NULL;
 957}
 958EXPORT_SYMBOL(dmi_find_device);
 959
 960/**
 961 *	dmi_get_date - parse a DMI date
 962 *	@field:	data index (see enum dmi_field)
 963 *	@yearp: optional out parameter for the year
 964 *	@monthp: optional out parameter for the month
 965 *	@dayp: optional out parameter for the day
 966 *
 967 *	The date field is assumed to be in the form resembling
 968 *	[mm[/dd]]/yy[yy] and the result is stored in the out
 969 *	parameters any or all of which can be omitted.
 970 *
 971 *	If the field doesn't exist, all out parameters are set to zero
 972 *	and false is returned.  Otherwise, true is returned with any
 973 *	invalid part of date set to zero.
 974 *
 975 *	On return, year, month and day are guaranteed to be in the
 976 *	range of [0,9999], [0,12] and [0,31] respectively.
 977 */
 978bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
 979{
 980	int year = 0, month = 0, day = 0;
 981	bool exists;
 982	const char *s, *y;
 983	char *e;
 984
 985	s = dmi_get_system_info(field);
 986	exists = s;
 987	if (!exists)
 988		goto out;
 989
 990	/*
 991	 * Determine year first.  We assume the date string resembles
 992	 * mm/dd/yy[yy] but the original code extracted only the year
 993	 * from the end.  Keep the behavior in the spirit of no
 994	 * surprises.
 995	 */
 996	y = strrchr(s, '/');
 997	if (!y)
 998		goto out;
 999
1000	y++;
1001	year = simple_strtoul(y, &e, 10);
1002	if (y != e && year < 100) {	/* 2-digit year */
1003		year += 1900;
1004		if (year < 1996)	/* no dates < spec 1.0 */
1005			year += 100;
1006	}
1007	if (year > 9999)		/* year should fit in %04d */
1008		year = 0;
1009
1010	/* parse the mm and dd */
1011	month = simple_strtoul(s, &e, 10);
1012	if (s == e || *e != '/' || !month || month > 12) {
1013		month = 0;
1014		goto out;
1015	}
1016
1017	s = e + 1;
1018	day = simple_strtoul(s, &e, 10);
1019	if (s == y || s == e || *e != '/' || day > 31)
1020		day = 0;
1021out:
1022	if (yearp)
1023		*yearp = year;
1024	if (monthp)
1025		*monthp = month;
1026	if (dayp)
1027		*dayp = day;
1028	return exists;
1029}
1030EXPORT_SYMBOL(dmi_get_date);
1031
1032/**
1033 *	dmi_get_bios_year - get a year out of DMI_BIOS_DATE field
1034 *
1035 *	Returns year on success, -ENXIO if DMI is not selected,
1036 *	or a different negative error code if DMI field is not present
1037 *	or not parseable.
1038 */
1039int dmi_get_bios_year(void)
1040{
1041	bool exists;
1042	int year;
1043
1044	exists = dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
1045	if (!exists)
1046		return -ENODATA;
1047
1048	return year ? year : -ERANGE;
1049}
1050EXPORT_SYMBOL(dmi_get_bios_year);
1051
1052/**
1053 *	dmi_walk - Walk the DMI table and get called back for every record
1054 *	@decode: Callback function
1055 *	@private_data: Private data to be passed to the callback function
1056 *
1057 *	Returns 0 on success, -ENXIO if DMI is not selected or not present,
1058 *	or a different negative error code if DMI walking fails.
1059 */
1060int dmi_walk(void (*decode)(const struct dmi_header *, void *),
1061	     void *private_data)
1062{
1063	u8 *buf;
1064
1065	if (!dmi_available)
1066		return -ENXIO;
1067
1068	buf = dmi_remap(dmi_base, dmi_len);
1069	if (buf == NULL)
1070		return -ENOMEM;
1071
1072	dmi_decode_table(buf, decode, private_data);
1073
1074	dmi_unmap(buf);
1075	return 0;
1076}
1077EXPORT_SYMBOL_GPL(dmi_walk);
1078
1079/**
1080 * dmi_match - compare a string to the dmi field (if exists)
1081 * @f: DMI field identifier
1082 * @str: string to compare the DMI field to
1083 *
1084 * Returns true if the requested field equals to the str (including NULL).
1085 */
1086bool dmi_match(enum dmi_field f, const char *str)
1087{
1088	const char *info = dmi_get_system_info(f);
1089
1090	if (info == NULL || str == NULL)
1091		return info == str;
1092
1093	return !strcmp(info, str);
1094}
1095EXPORT_SYMBOL_GPL(dmi_match);
1096
1097void dmi_memdev_name(u16 handle, const char **bank, const char **device)
1098{
1099	int n;
1100
1101	if (dmi_memdev == NULL)
1102		return;
1103
1104	for (n = 0; n < dmi_memdev_nr; n++) {
1105		if (handle == dmi_memdev[n].handle) {
1106			*bank = dmi_memdev[n].bank;
1107			*device = dmi_memdev[n].device;
1108			break;
1109		}
1110	}
1111}
1112EXPORT_SYMBOL_GPL(dmi_memdev_name);
1113
1114u64 dmi_memdev_size(u16 handle)
1115{
1116	int n;
1117
1118	if (dmi_memdev) {
1119		for (n = 0; n < dmi_memdev_nr; n++) {
1120			if (handle == dmi_memdev[n].handle)
1121				return dmi_memdev[n].size;
1122		}
1123	}
1124	return ~0ull;
1125}
1126EXPORT_SYMBOL_GPL(dmi_memdev_size);