dmi_scan.c

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#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/bootmem.h>
#include <linux/random.h>
#include <asm/dmi.h>

/*
 * DMI stands for "Desktop Management Interface".  It is part
 * of and an antecedent to, SMBIOS, which stands for System
 * Management BIOS.  See further: http://www.dmtf.org/standards
 */
static char dmi_empty_string[] = "        ";

/*
 * Catch too early calls to dmi_check_system():
 */
static int dmi_initialized;

static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
{
    const u8 *bp = ((u8 *) dm) + dm->length;

    if (s) {
        s--;
        while (s > 0 && *bp) {
            bp += strlen(bp) + 1;
            s--;
        }

        if (*bp != 0) {
            size_t len = strlen(bp)+1;
            size_t cmp_len = len > 8 ? 8 : len;

            if (!memcmp(bp, dmi_empty_string, cmp_len))
                return dmi_empty_string;
            return bp;
        }
    }

    return "";
}

static char * __init dmi_string(const struct dmi_header *dm, u8 s)
{
    const char *bp = dmi_string_nosave(dm, s);
    char *str;
    size_t len;

    if (bp == dmi_empty_string)
        return dmi_empty_string;

    len = strlen(bp) + 1;
    str = dmi_alloc(len);
    if (str != NULL)
        strcpy(str, bp);
    else
        printk(KERN_ERR "dmi_string: cannot allocate %Zu bytes.\n", len);

    return str;
}

/*
 *  We have to be cautious here. We have seen BIOSes with DMI pointers
 *  pointing to completely the wrong place for example
 */
static void dmi_table(u8 *buf, int len, int num,
              void (*decode)(const struct dmi_header *, void *),
              void *private_data)
{
    u8 *data = buf;
    int i = 0;

    /*
     *  Stop when we see all the items the table claimed to have
     *  OR we run off the end of the table (also happens)
     */
    while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
        const struct dmi_header *dm = (const struct dmi_header *)data;

        /*
         *  We want to know the total length (formatted area and
         *  strings) before decoding to make sure we won't run off the
         *  table in dmi_decode or dmi_string
         */
        data += dm->length;
        while ((data - buf < len - 1) && (data[0] || data[1]))
            data++;
        if (data - buf < len - 1)
            decode(dm, private_data);
        data += 2;
        i++;
    }
}

static u32 dmi_base;
static u16 dmi_len;
static u16 dmi_num;

static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
        void *))
{
    u8 *buf;

    buf = dmi_ioremap(dmi_base, dmi_len);
    if (buf == NULL)
        return -1;

    dmi_table(buf, dmi_len, dmi_num, decode, NULL);

    add_device_randomness(buf, dmi_len);

    dmi_iounmap(buf, dmi_len);
    return 0;
}

static int __init dmi_checksum(const u8 *buf)
{
    u8 sum = 0;
    int a;

    for (a = 0; a < 15; a++)
        sum += buf[a];

    return sum == 0;
}

static char *dmi_ident[DMI_STRING_MAX];
static LIST_HEAD(dmi_devices);
int dmi_available;

/*
 *  Save a DMI string
 */
static void __init dmi_save_ident(const struct dmi_header *dm, int slot, int string)
{
    const char *d = (const char*) dm;
    char *p;

    if (dmi_ident[slot])
        return;

    p = dmi_string(dm, d[string]);
    if (p == NULL)
        return;

    dmi_ident[slot] = p;
}

static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int index)
{
    const u8 *d = (u8*) dm + index;
    char *s;
    int is_ff = 1, is_00 = 1, i;

    if (dmi_ident[slot])
        return;

    for (i = 0; i < 16 && (is_ff || is_00); i++) {
        if(d[i] != 0x00) is_ff = 0;
        if(d[i] != 0xFF) is_00 = 0;
    }

    if (is_ff || is_00)
        return;

    s = dmi_alloc(16*2+4+1);
    if (!s)
        return;

    sprintf(s, "%pUB", d);

        dmi_ident[slot] = s;
}

static void __init dmi_save_type(const struct dmi_header *dm, int slot, int index)
{
    const u8 *d = (u8*) dm + index;
    char *s;

    if (dmi_ident[slot])
        return;

    s = dmi_alloc(4);
    if (!s)
        return;

    sprintf(s, "%u", *d & 0x7F);
    dmi_ident[slot] = s;
}

static void __init dmi_save_one_device(int type, const char *name)
{
    struct dmi_device *dev;

    /* No duplicate device */
    if (dmi_find_device(type, name, NULL))
        return;

    dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
    if (!dev) {
        printk(KERN_ERR "dmi_save_one_device: out of memory.\n");
        return;
    }

    dev->type = type;
    strcpy((char *)(dev + 1), name);
    dev->name = (char *)(dev + 1);
    dev->device_data = NULL;
    list_add(&dev->list, &dmi_devices);
}

static void __init dmi_save_devices(const struct dmi_header *dm)
{
    int i, count = (dm->length - sizeof(struct dmi_header)) / 2;

    for (i = 0; i < count; i++) {
        const char *d = (char *)(dm + 1) + (i * 2);

        /* Skip disabled device */
        if ((*d & 0x80) == 0)
            continue;

        dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
    }
}

static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
{
    int i, count = *(u8 *)(dm + 1);
    struct dmi_device *dev;

    for (i = 1; i <= count; i++) {
        char *devname = dmi_string(dm, i);

        if (devname == dmi_empty_string)
            continue;

        dev = dmi_alloc(sizeof(*dev));
        if (!dev) {
            printk(KERN_ERR
               "dmi_save_oem_strings_devices: out of memory.\n");
            break;
        }

        dev->type = DMI_DEV_TYPE_OEM_STRING;
        dev->name = devname;
        dev->device_data = NULL;

        list_add(&dev->list, &dmi_devices);
    }
}

static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
{
    struct dmi_device *dev;
    void * data;

    data = dmi_alloc(dm->length);
    if (data == NULL) {
        printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
        return;
    }

    memcpy(data, dm, dm->length);

    dev = dmi_alloc(sizeof(*dev));
    if (!dev) {
        printk(KERN_ERR "dmi_save_ipmi_device: out of memory.\n");
        return;
    }

    dev->type = DMI_DEV_TYPE_IPMI;
    dev->name = "IPMI controller";
    dev->device_data = data;

    list_add_tail(&dev->list, &dmi_devices);
}

static void __init dmi_save_dev_onboard(int instance, int segment, int bus,
                    int devfn, const char *name)
{
    struct dmi_dev_onboard *onboard_dev;

    onboard_dev = dmi_alloc(sizeof(*onboard_dev) + strlen(name) + 1);
    if (!onboard_dev) {
        printk(KERN_ERR "dmi_save_dev_onboard: out of memory.\n");
        return;
    }
    onboard_dev->instance = instance;
    onboard_dev->segment = segment;
    onboard_dev->bus = bus;
    onboard_dev->devfn = devfn;

    strcpy((char *)&onboard_dev[1], name);
    onboard_dev->dev.type = DMI_DEV_TYPE_DEV_ONBOARD;
    onboard_dev->dev.name = (char *)&onboard_dev[1];
    onboard_dev->dev.device_data = onboard_dev;

    list_add(&onboard_dev->dev.list, &dmi_devices);
}

static void __init dmi_save_extended_devices(const struct dmi_header *dm)
{
    const u8 *d = (u8*) dm + 5;

    /* Skip disabled device */
    if ((*d & 0x80) == 0)
        return;

    dmi_save_dev_onboard(*(d+1), *(u16 *)(d+2), *(d+4), *(d+5),
                 dmi_string_nosave(dm, *(d-1)));
    dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d - 1)));
}

/*
 *  Process a DMI table entry. Right now all we care about are the BIOS
 *  and machine entries. For 2.5 we should pull the smbus controller info
 *  out of here.
 */
static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
{
    switch(dm->type) {
    case 0:     /* BIOS Information */
        dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
        dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
        dmi_save_ident(dm, DMI_BIOS_DATE, 8);
        break;
    case 1:     /* System Information */
        dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
        dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
        dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
        dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
        dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
        break;
    case 2:     /* Base Board Information */
        dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
        dmi_save_ident(dm, DMI_BOARD_NAME, 5);
        dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
        dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
        dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
        break;
    case 3:     /* Chassis Information */
        dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
        dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
        dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
        dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
        dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
        break;
    case 10:    /* Onboard Devices Information */
        dmi_save_devices(dm);
        break;
    case 11:    /* OEM Strings */
        dmi_save_oem_strings_devices(dm);
        break;
    case 38:    /* IPMI Device Information */
        dmi_save_ipmi_device(dm);
        break;
    case 41:    /* Onboard Devices Extended Information */
        dmi_save_extended_devices(dm);
    }
}

static void __init print_filtered(const char *info)
{
    const char *p;

    if (!info)
        return;

    for (p = info; *p; p++)
        if (isprint(*p))
            printk(KERN_CONT "%c", *p);
        else
            printk(KERN_CONT "\\x%02x", *p & 0xff);
}

static void __init dmi_dump_ids(void)
{
    const char *board;  /* Board Name is optional */

    printk(KERN_DEBUG "DMI: ");
    print_filtered(dmi_get_system_info(DMI_SYS_VENDOR));
    printk(KERN_CONT " ");
    print_filtered(dmi_get_system_info(DMI_PRODUCT_NAME));
    board = dmi_get_system_info(DMI_BOARD_NAME);
    if (board) {
        printk(KERN_CONT "/");
        print_filtered(board);
    }
    printk(KERN_CONT ", BIOS ");
    print_filtered(dmi_get_system_info(DMI_BIOS_VERSION));
    printk(KERN_CONT " ");
    print_filtered(dmi_get_system_info(DMI_BIOS_DATE));
    printk(KERN_CONT "\n");
}

static int __init dmi_present(const char __iomem *p)
{
    u8 buf[15];

    memcpy_fromio(buf, p, 15);
    if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
        dmi_num = (buf[13] << 8) | buf[12];
        dmi_len = (buf[7] << 8) | buf[6];
        dmi_base = (buf[11] << 24) | (buf[10] << 16) |
            (buf[9] << 8) | buf[8];

        /*
         * DMI version 0.0 means that the real version is taken from
         * the SMBIOS version, which we don't know at this point.
         */
        if (buf[14] != 0)
            printk(KERN_INFO "DMI %d.%d present.\n",
                   buf[14] >> 4, buf[14] & 0xF);
        else
            printk(KERN_INFO "DMI present.\n");
        if (dmi_walk_early(dmi_decode) == 0) {
            dmi_dump_ids();
            return 0;
        }
    }
    return 1;
}

void __init dmi_scan_machine(void)
{
    char __iomem *p, *q;
    int rc;

    if (efi_enabled) {
        if (efi.smbios == EFI_INVALID_TABLE_ADDR)
            goto error;

        /* This is called as a core_initcall() because it isn't
         * needed during early boot.  This also means we can
         * iounmap the space when we're done with it.
         */
        p = dmi_ioremap(efi.smbios, 32);
        if (p == NULL)
            goto error;

        rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
        dmi_iounmap(p, 32);
        if (!rc) {
            dmi_available = 1;
            goto out;
        }
    }
    else {
        /*
         * no iounmap() for that ioremap(); it would be a no-op, but
         * it's so early in setup that sucker gets confused into doing
         * what it shouldn't if we actually call it.
         */
        p = dmi_ioremap(0xF0000, 0x10000);
        if (p == NULL)
            goto error;

        for (q = p; q < p + 0x10000; q += 16) {
            rc = dmi_present(q);
            if (!rc) {
                dmi_available = 1;
                dmi_iounmap(p, 0x10000);
                goto out;
            }
        }
        dmi_iounmap(p, 0x10000);
    }
 error:
    printk(KERN_INFO "DMI not present or invalid.\n");
 out:
    dmi_initialized = 1;
}

static bool dmi_matches(const struct dmi_system_id *dmi)
{
    int i;

    WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n");

    for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
        int s = dmi->matches[i].slot;
        if (s == DMI_NONE)
            break;
        if (dmi_ident[s]
            && strstr(dmi_ident[s], dmi->matches[i].substr))
            continue;
        /* No match */
        return false;
    }
    return true;
}

static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
{
    return dmi->matches[0].slot == DMI_NONE;
}

int dmi_check_system(const struct dmi_system_id *list)
{
    int count = 0;
    const struct dmi_system_id *d;

    for (d = list; !dmi_is_end_of_table(d); d++)
        if (dmi_matches(d)) {
            count++;
            if (d->callback && d->callback(d))
                break;
        }

    return count;
}
EXPORT_SYMBOL(dmi_check_system);

const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
{
    const struct dmi_system_id *d;

    for (d = list; !dmi_is_end_of_table(d); d++)
        if (dmi_matches(d))
            return d;

    return NULL;
}
EXPORT_SYMBOL(dmi_first_match);

const char *dmi_get_system_info(int field)
{
    return dmi_ident[field];
}
EXPORT_SYMBOL(dmi_get_system_info);

int dmi_name_in_serial(const char *str)
{
    int f = DMI_PRODUCT_SERIAL;
    if (dmi_ident[f] && strstr(dmi_ident[f], str))
        return 1;
    return 0;
}

int dmi_name_in_vendors(const char *str)
{
    static int fields[] = { DMI_SYS_VENDOR, DMI_BOARD_VENDOR, DMI_NONE };
    int i;
    for (i = 0; fields[i] != DMI_NONE; i++) {
        int f = fields[i];
        if (dmi_ident[f] && strstr(dmi_ident[f], str))
            return 1;
    }
    return 0;
}
EXPORT_SYMBOL(dmi_name_in_vendors);

const struct dmi_device * dmi_find_device(int type, const char *name,
                    const struct dmi_device *from)
{
    const struct list_head *head = from ? &from->list : &dmi_devices;
    struct list_head *d;

    for(d = head->next; d != &dmi_devices; d = d->next) {
        const struct dmi_device *dev =
            list_entry(d, struct dmi_device, list);

        if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
            ((name == NULL) || (strcmp(dev->name, name) == 0)))
            return dev;
    }

    return NULL;
}
EXPORT_SYMBOL(dmi_find_device);

bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
{
    int year = 0, month = 0, day = 0;
    bool exists;
    const char *s, *y;
    char *e;

    s = dmi_get_system_info(field);
    exists = s;
    if (!exists)
        goto out;

    /*
     * Determine year first.  We assume the date string resembles
     * mm/dd/yy[yy] but the original code extracted only the year
     * from the end.  Keep the behavior in the spirit of no
     * surprises.
     */
    y = strrchr(s, '/');
    if (!y)
        goto out;

    y++;
    year = simple_strtoul(y, &e, 10);
    if (y != e && year < 100) { /* 2-digit year */
        year += 1900;
        if (year < 1996)    /* no dates < spec 1.0 */
            year += 100;
    }
    if (year > 9999)        /* year should fit in %04d */
        year = 0;

    /* parse the mm and dd */
    month = simple_strtoul(s, &e, 10);
    if (s == e || *e != '/' || !month || month > 12) {
        month = 0;
        goto out;
    }

    s = e + 1;
    day = simple_strtoul(s, &e, 10);
    if (s == y || s == e || *e != '/' || day > 31)
        day = 0;
out:
    if (yearp)
        *yearp = year;
    if (monthp)
        *monthp = month;
    if (dayp)
        *dayp = day;
    return exists;
}
EXPORT_SYMBOL(dmi_get_date);

int dmi_walk(void (*decode)(const struct dmi_header *, void *),
         void *private_data)
{
    u8 *buf;

    if (!dmi_available)
        return -1;

    buf = ioremap(dmi_base, dmi_len);
    if (buf == NULL)
        return -1;

    dmi_table(buf, dmi_len, dmi_num, decode, private_data);

    iounmap(buf);
    return 0;
}
EXPORT_SYMBOL_GPL(dmi_walk);

bool dmi_match(enum dmi_field f, const char *str)
{
    const char *info = dmi_get_system_info(f);

    if (info == NULL || str == NULL)
        return info == str;

    return !strcmp(info, str);
}
EXPORT_SYMBOL_GPL(dmi_match);