linux/drivers/firmware/dmi_scan.c
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   1#include <linux/types.h>
   2#include <linux/string.h>
   3#include <linux/init.h>
   4#include <linux/module.h>
   5#include <linux/dmi.h>
   6#include <linux/efi.h>
   7#include <linux/bootmem.h>
   8#include <linux/slab.h>
   9#include <asm/dmi.h>
  10
  11/*
  12 * DMI stands for "Desktop Management Interface".  It is part
  13 * of and an antecedent to, SMBIOS, which stands for System
  14 * Management BIOS.  See further: http://www.dmtf.org/standards
  15 */
  16static char dmi_empty_string[] = "        ";
  17
  18/*
  19 * Catch too early calls to dmi_check_system():
  20 */
  21static int dmi_initialized;
  22
  23static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
  24{
  25        const u8 *bp = ((u8 *) dm) + dm->length;
  26
  27        if (s) {
  28                s--;
  29                while (s > 0 && *bp) {
  30                        bp += strlen(bp) + 1;
  31                        s--;
  32                }
  33
  34                if (*bp != 0) {
  35                        size_t len = strlen(bp)+1;
  36                        size_t cmp_len = len > 8 ? 8 : len;
  37
  38                        if (!memcmp(bp, dmi_empty_string, cmp_len))
  39                                return dmi_empty_string;
  40                        return bp;
  41                }
  42        }
  43
  44        return "";
  45}
  46
  47static char * __init dmi_string(const struct dmi_header *dm, u8 s)
  48{
  49        const char *bp = dmi_string_nosave(dm, s);
  50        char *str;
  51        size_t len;
  52
  53        if (bp == dmi_empty_string)
  54                return dmi_empty_string;
  55
  56        len = strlen(bp) + 1;
  57        str = dmi_alloc(len);
  58        if (str != NULL)
  59                strcpy(str, bp);
  60        else
  61                printk(KERN_ERR "dmi_string: cannot allocate %Zu bytes.\n", len);
  62
  63        return str;
  64}
  65
  66/*
  67 *      We have to be cautious here. We have seen BIOSes with DMI pointers
  68 *      pointing to completely the wrong place for example
  69 */
  70static void dmi_table(u8 *buf, int len, int num,
  71                      void (*decode)(const struct dmi_header *))
  72{
  73        u8 *data = buf;
  74        int i = 0;
  75
  76        /*
  77         *      Stop when we see all the items the table claimed to have
  78         *      OR we run off the end of the table (also happens)
  79         */
  80        while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
  81                const struct dmi_header *dm = (const struct dmi_header *)data;
  82
  83                /*
  84                 *  We want to know the total length (formatted area and
  85                 *  strings) before decoding to make sure we won't run off the
  86                 *  table in dmi_decode or dmi_string
  87                 */
  88                data += dm->length;
  89                while ((data - buf < len - 1) && (data[0] || data[1]))
  90                        data++;
  91                if (data - buf < len - 1)
  92                        decode(dm);
  93                data += 2;
  94                i++;
  95        }
  96}
  97
  98static u32 dmi_base;
  99static u16 dmi_len;
 100static u16 dmi_num;
 101
 102static int __init dmi_walk_early(void (*decode)(const struct dmi_header *))
 103{
 104        u8 *buf;
 105
 106        buf = dmi_ioremap(dmi_base, dmi_len);
 107        if (buf == NULL)
 108                return -1;
 109
 110        dmi_table(buf, dmi_len, dmi_num, decode);
 111
 112        dmi_iounmap(buf, dmi_len);
 113        return 0;
 114}
 115
 116static int __init dmi_checksum(const u8 *buf)
 117{
 118        u8 sum = 0;
 119        int a;
 120
 121        for (a = 0; a < 15; a++)
 122                sum += buf[a];
 123
 124        return sum == 0;
 125}
 126
 127static char *dmi_ident[DMI_STRING_MAX];
 128static LIST_HEAD(dmi_devices);
 129int dmi_available;
 130
 131/*
 132 *      Save a DMI string
 133 */
 134static void __init dmi_save_ident(const struct dmi_header *dm, int slot, int string)
 135{
 136        const char *d = (const char*) dm;
 137        char *p;
 138
 139        if (dmi_ident[slot])
 140                return;
 141
 142        p = dmi_string(dm, d[string]);
 143        if (p == NULL)
 144                return;
 145
 146        dmi_ident[slot] = p;
 147}
 148
 149static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int index)
 150{
 151        const u8 *d = (u8*) dm + index;
 152        char *s;
 153        int is_ff = 1, is_00 = 1, i;
 154
 155        if (dmi_ident[slot])
 156                return;
 157
 158        for (i = 0; i < 16 && (is_ff || is_00); i++) {
 159                if(d[i] != 0x00) is_ff = 0;
 160                if(d[i] != 0xFF) is_00 = 0;
 161        }
 162
 163        if (is_ff || is_00)
 164                return;
 165
 166        s = dmi_alloc(16*2+4+1);
 167        if (!s)
 168                return;
 169
 170        sprintf(s,
 171                "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
 172                d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
 173                d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
 174
 175        dmi_ident[slot] = s;
 176}
 177
 178static void __init dmi_save_type(const struct dmi_header *dm, int slot, int index)
 179{
 180        const u8 *d = (u8*) dm + index;
 181        char *s;
 182
 183        if (dmi_ident[slot])
 184                return;
 185
 186        s = dmi_alloc(4);
 187        if (!s)
 188                return;
 189
 190        sprintf(s, "%u", *d & 0x7F);
 191        dmi_ident[slot] = s;
 192}
 193
 194static void __init dmi_save_one_device(int type, const char *name)
 195{
 196        struct dmi_device *dev;
 197
 198        /* No duplicate device */
 199        if (dmi_find_device(type, name, NULL))
 200                return;
 201
 202        dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
 203        if (!dev) {
 204                printk(KERN_ERR "dmi_save_one_device: out of memory.\n");
 205                return;
 206        }
 207
 208        dev->type = type;
 209        strcpy((char *)(dev + 1), name);
 210        dev->name = (char *)(dev + 1);
 211        dev->device_data = NULL;
 212        list_add(&dev->list, &dmi_devices);
 213}
 214
 215static void __init dmi_save_devices(const struct dmi_header *dm)
 216{
 217        int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
 218
 219        for (i = 0; i < count; i++) {
 220                const char *d = (char *)(dm + 1) + (i * 2);
 221
 222                /* Skip disabled device */
 223                if ((*d & 0x80) == 0)
 224                        continue;
 225
 226                dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
 227        }
 228}
 229
 230static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
 231{
 232        int i, count = *(u8 *)(dm + 1);
 233        struct dmi_device *dev;
 234
 235        for (i = 1; i <= count; i++) {
 236                char *devname = dmi_string(dm, i);
 237
 238                if (devname == dmi_empty_string)
 239                        continue;
 240
 241                dev = dmi_alloc(sizeof(*dev));
 242                if (!dev) {
 243                        printk(KERN_ERR
 244                           "dmi_save_oem_strings_devices: out of memory.\n");
 245                        break;
 246                }
 247
 248                dev->type = DMI_DEV_TYPE_OEM_STRING;
 249                dev->name = devname;
 250                dev->device_data = NULL;
 251
 252                list_add(&dev->list, &dmi_devices);
 253        }
 254}
 255
 256static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
 257{
 258        struct dmi_device *dev;
 259        void * data;
 260
 261        data = dmi_alloc(dm->length);
 262        if (data == NULL) {
 263                printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
 264                return;
 265        }
 266
 267        memcpy(data, dm, dm->length);
 268
 269        dev = dmi_alloc(sizeof(*dev));
 270        if (!dev) {
 271                printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
 272                return;
 273        }
 274
 275        dev->type = DMI_DEV_TYPE_IPMI;
 276        dev->name = "IPMI controller";
 277        dev->device_data = data;
 278
 279        list_add_tail(&dev->list, &dmi_devices);
 280}
 281
 282static void __init dmi_save_extended_devices(const struct dmi_header *dm)
 283{
 284        const u8 *d = (u8*) dm + 5;
 285
 286        /* Skip disabled device */
 287        if ((*d & 0x80) == 0)
 288                return;
 289
 290        dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d - 1)));
 291}
 292
 293/*
 294 *      Process a DMI table entry. Right now all we care about are the BIOS
 295 *      and machine entries. For 2.5 we should pull the smbus controller info
 296 *      out of here.
 297 */
 298static void __init dmi_decode(const struct dmi_header *dm)
 299{
 300        switch(dm->type) {
 301        case 0:         /* BIOS Information */
 302                dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
 303                dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
 304                dmi_save_ident(dm, DMI_BIOS_DATE, 8);
 305                break;
 306        case 1:         /* System Information */
 307                dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
 308                dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
 309                dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
 310                dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
 311                dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
 312                break;
 313        case 2:         /* Base Board Information */
 314                dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
 315                dmi_save_ident(dm, DMI_BOARD_NAME, 5);
 316                dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
 317                dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
 318                dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
 319                break;
 320        case 3:         /* Chassis Information */
 321                dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
 322                dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
 323                dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
 324                dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
 325                dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
 326                break;
 327        case 10:        /* Onboard Devices Information */
 328                dmi_save_devices(dm);
 329                break;
 330        case 11:        /* OEM Strings */
 331                dmi_save_oem_strings_devices(dm);
 332                break;
 333        case 38:        /* IPMI Device Information */
 334                dmi_save_ipmi_device(dm);
 335                break;
 336        case 41:        /* Onboard Devices Extended Information */
 337                dmi_save_extended_devices(dm);
 338        }
 339}
 340
 341static int __init dmi_present(const char __iomem *p)
 342{
 343        u8 buf[15];
 344
 345        memcpy_fromio(buf, p, 15);
 346        if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
 347                dmi_num = (buf[13] << 8) | buf[12];
 348                dmi_len = (buf[7] << 8) | buf[6];
 349                dmi_base = (buf[11] << 24) | (buf[10] << 16) |
 350                        (buf[9] << 8) | buf[8];
 351
 352                /*
 353                 * DMI version 0.0 means that the real version is taken from
 354                 * the SMBIOS version, which we don't know at this point.
 355                 */
 356                if (buf[14] != 0)
 357                        printk(KERN_INFO "DMI %d.%d present.\n",
 358                               buf[14] >> 4, buf[14] & 0xF);
 359                else
 360                        printk(KERN_INFO "DMI present.\n");
 361                if (dmi_walk_early(dmi_decode) == 0)
 362                        return 0;
 363        }
 364        return 1;
 365}
 366
 367void __init dmi_scan_machine(void)
 368{
 369        char __iomem *p, *q;
 370        int rc;
 371
 372        if (efi_enabled) {
 373                if (efi.smbios == EFI_INVALID_TABLE_ADDR)
 374                        goto error;
 375
 376                /* This is called as a core_initcall() because it isn't
 377                 * needed during early boot.  This also means we can
 378                 * iounmap the space when we're done with it.
 379                 */
 380                p = dmi_ioremap(efi.smbios, 32);
 381                if (p == NULL)
 382                        goto error;
 383
 384                rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
 385                dmi_iounmap(p, 32);
 386                if (!rc) {
 387                        dmi_available = 1;
 388                        goto out;
 389                }
 390        }
 391        else {
 392                /*
 393                 * no iounmap() for that ioremap(); it would be a no-op, but
 394                 * it's so early in setup that sucker gets confused into doing
 395                 * what it shouldn't if we actually call it.
 396                 */
 397                p = dmi_ioremap(0xF0000, 0x10000);
 398                if (p == NULL)
 399                        goto error;
 400
 401                for (q = p; q < p + 0x10000; q += 16) {
 402                        rc = dmi_present(q);
 403                        if (!rc) {
 404                                dmi_available = 1;
 405                                dmi_iounmap(p, 0x10000);
 406                                goto out;
 407                        }
 408                }
 409                dmi_iounmap(p, 0x10000);
 410        }
 411 error:
 412        printk(KERN_INFO "DMI not present or invalid.\n");
 413 out:
 414        dmi_initialized = 1;
 415}
 416
 417/**
 418 *      dmi_check_system - check system DMI data
 419 *      @list: array of dmi_system_id structures to match against
 420 *              All non-null elements of the list must match
 421 *              their slot's (field index's) data (i.e., each
 422 *              list string must be a substring of the specified
 423 *              DMI slot's string data) to be considered a
 424 *              successful match.
 425 *
 426 *      Walk the blacklist table running matching functions until someone
 427 *      returns non zero or we hit the end. Callback function is called for
 428 *      each successful match. Returns the number of matches.
 429 */
 430int dmi_check_system(const struct dmi_system_id *list)
 431{
 432        int i, count = 0;
 433        const struct dmi_system_id *d = list;
 434
 435        WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n");
 436
 437        while (d->ident) {
 438                for (i = 0; i < ARRAY_SIZE(d->matches); i++) {
 439                        int s = d->matches[i].slot;
 440                        if (s == DMI_NONE)
 441                                continue;
 442                        if (dmi_ident[s] && strstr(dmi_ident[s], d->matches[i].substr))
 443                                continue;
 444                        /* No match */
 445                        goto fail;
 446                }
 447                count++;
 448                if (d->callback && d->callback(d))
 449                        break;
 450fail:           d++;
 451        }
 452
 453        return count;
 454}
 455EXPORT_SYMBOL(dmi_check_system);
 456
 457/**
 458 *      dmi_get_system_info - return DMI data value
 459 *      @field: data index (see enum dmi_field)
 460 *
 461 *      Returns one DMI data value, can be used to perform
 462 *      complex DMI data checks.
 463 */
 464const char *dmi_get_system_info(int field)
 465{
 466        return dmi_ident[field];
 467}
 468EXPORT_SYMBOL(dmi_get_system_info);
 469
 470
 471/**
 472 *      dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.
 473 *      @str:   Case sensitive Name
 474 */
 475int dmi_name_in_vendors(const char *str)
 476{
 477        static int fields[] = { DMI_BIOS_VENDOR, DMI_BIOS_VERSION, DMI_SYS_VENDOR,
 478                                DMI_PRODUCT_NAME, DMI_PRODUCT_VERSION, DMI_BOARD_VENDOR,
 479                                DMI_BOARD_NAME, DMI_BOARD_VERSION, DMI_NONE };
 480        int i;
 481        for (i = 0; fields[i] != DMI_NONE; i++) {
 482                int f = fields[i];
 483                if (dmi_ident[f] && strstr(dmi_ident[f], str))
 484                        return 1;
 485        }
 486        return 0;
 487}
 488EXPORT_SYMBOL(dmi_name_in_vendors);
 489
 490/**
 491 *      dmi_find_device - find onboard device by type/name
 492 *      @type: device type or %DMI_DEV_TYPE_ANY to match all device types
 493 *      @name: device name string or %NULL to match all
 494 *      @from: previous device found in search, or %NULL for new search.
 495 *
 496 *      Iterates through the list of known onboard devices. If a device is
 497 *      found with a matching @vendor and @device, a pointer to its device
 498 *      structure is returned.  Otherwise, %NULL is returned.
 499 *      A new search is initiated by passing %NULL as the @from argument.
 500 *      If @from is not %NULL, searches continue from next device.
 501 */
 502const struct dmi_device * dmi_find_device(int type, const char *name,
 503                                    const struct dmi_device *from)
 504{
 505        const struct list_head *head = from ? &from->list : &dmi_devices;
 506        struct list_head *d;
 507
 508        for(d = head->next; d != &dmi_devices; d = d->next) {
 509                const struct dmi_device *dev =
 510                        list_entry(d, struct dmi_device, list);
 511
 512                if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
 513                    ((name == NULL) || (strcmp(dev->name, name) == 0)))
 514                        return dev;
 515        }
 516
 517        return NULL;
 518}
 519EXPORT_SYMBOL(dmi_find_device);
 520
 521/**
 522 *      dmi_get_year - Return year of a DMI date
 523 *      @field: data index (like dmi_get_system_info)
 524 *
 525 *      Returns -1 when the field doesn't exist. 0 when it is broken.
 526 */
 527int dmi_get_year(int field)
 528{
 529        int year;
 530        const char *s = dmi_get_system_info(field);
 531
 532        if (!s)
 533                return -1;
 534        if (*s == '\0')
 535                return 0;
 536        s = strrchr(s, '/');
 537        if (!s)
 538                return 0;
 539
 540        s += 1;
 541        year = simple_strtoul(s, NULL, 0);
 542        if (year && year < 100) {       /* 2-digit year */
 543                year += 1900;
 544                if (year < 1996)        /* no dates < spec 1.0 */
 545                        year += 100;
 546        }
 547
 548        return year;
 549}
 550
 551/**
 552 *      dmi_walk - Walk the DMI table and get called back for every record
 553 *      @decode: Callback function
 554 *
 555 *      Returns -1 when the DMI table can't be reached, 0 on success.
 556 */
 557int dmi_walk(void (*decode)(const struct dmi_header *))
 558{
 559        u8 *buf;
 560
 561        if (!dmi_available)
 562                return -1;
 563
 564        buf = ioremap(dmi_base, dmi_len);
 565        if (buf == NULL)
 566                return -1;
 567
 568        dmi_table(buf, dmi_len, dmi_num, decode);
 569
 570        iounmap(buf);
 571        return 0;
 572}
 573EXPORT_SYMBOL_GPL(dmi_walk);
 574