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