#include <linux/types.h>
#include <linux/string.h>
#include <linux/bug.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/dmi.h>
#include <syscall.h>

static void *dmi_alloc(unsigned len)
{
    return __builtin_malloc(len);
};

/*
 * 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 const char dmi_empty_string[] = "        ";

static u16 dmi_ver;
/*
 * Catch too early calls to dmi_check_system():
 */
static int dmi_initialized;

/* DMI system identification string used during boot */
static char dmi_ids_string[128];

static struct dmi_memdev_info {
	const char *device;
	const char *bank;
	u16 handle;
} *dmi_memdev;
static int dmi_memdev_nr;

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 const 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);

    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 = (u8*)MapIoMem(dmi_base, dmi_len, PG_SW);
	if (buf == NULL)
		return -1;

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

	FreeKernelSpace(buf);

    return 0;
}

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

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

    return sum == 0;
}

static const 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;
    const 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_00 = 0;
        if (d[i] != 0xFF)
            is_ff = 0;
    }

    if (is_ff || is_00)
        return;

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

    /*
     * As of version 2.6 of the SMBIOS specification, the first 3 fields of
     * the UUID are supposed to be little-endian encoded.  The specification
     * says that this is the defacto standard.
     */
    if (dmi_ver >= 0x0206)
        sprintf(s, "%pUL", d);
    else
        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)
        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++) {
        const char *devname = dmi_string(dm, i);

        if (devname == dmi_empty_string)
            continue;

        dev = dmi_alloc(sizeof(*dev));
        if (!dev)
            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)
		return;

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

	dev = dmi_alloc(sizeof(*dev));
	if (!dev)
		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)
		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 int __init print_filtered(char *buf, size_t len, const char *info)
{
	int c = 0;
	const char *p;

	if (!info)
		return c;

	for (p = info; *p; p++)
		if (isprint(*p))
			c += scnprintf(buf + c, len - c, "%c", *p);
		else
			c += scnprintf(buf + c, len - c, "\\x%02x", *p & 0xff);
	return c;
}

static void __init dmi_format_ids(char *buf, size_t len)
{
    int c = 0;
    const char *board;  /* Board Name is optional */

    c += print_filtered(buf + c, len - c,
                dmi_get_system_info(DMI_SYS_VENDOR));
    c += scnprintf(buf + c, len - c, " ");
    c += print_filtered(buf + c, len - c,
                dmi_get_system_info(DMI_PRODUCT_NAME));

    board = dmi_get_system_info(DMI_BOARD_NAME);
    if (board) {
        c += scnprintf(buf + c, len - c, "/");
        c += print_filtered(buf + c, len - c, board);
    }
    c += scnprintf(buf + c, len - c, ", BIOS ");
    c += print_filtered(buf + c, len - c,
                dmi_get_system_info(DMI_BIOS_VERSION));
    c += scnprintf(buf + c, len - c, " ");
    c += print_filtered(buf + c, len - c,
                dmi_get_system_info(DMI_BIOS_DATE));
}

/*
 * Check for DMI/SMBIOS headers in the system firmware image.  Any
 * SMBIOS header must start 16 bytes before the DMI header, so take a
 * 32 byte buffer and check for DMI at offset 16 and SMBIOS at offset
 * 0.  If the DMI header is present, set dmi_ver accordingly (SMBIOS
 * takes precedence) and return 0.  Otherwise return 1.
 */
static int __init dmi_present(const u8 *buf)
{
    int smbios_ver;

    if (memcmp(buf, "_SM_", 4) == 0 &&
        buf[5] < 32 && dmi_checksum(buf, buf[5])) {
        smbios_ver = (buf[6] << 8) + buf[7];

        /* Some BIOS report weird SMBIOS version, fix that up */
        switch (smbios_ver) {
        case 0x021F:
        case 0x0221:
            pr_debug("SMBIOS version fixup(2.%d->2.%d)\n",
                 smbios_ver & 0xFF, 3);
            smbios_ver = 0x0203;
            break;
        case 0x0233:
            pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6);
            smbios_ver = 0x0206;
            break;
        }
    } else {
        smbios_ver = 0;
    }

    buf += 16;

    if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {
        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];

        if (dmi_walk_early(dmi_decode) == 0) {
            if (smbios_ver) {
                dmi_ver = smbios_ver;
                pr_info("SMBIOS %d.%d present.\n",
                       dmi_ver >> 8, dmi_ver & 0xFF);
            } else {
                dmi_ver = (buf[14] & 0xF0) << 4 |
                       (buf[14] & 0x0F);
                pr_info("Legacy DMI %d.%d present.\n",
                       dmi_ver >> 8, dmi_ver & 0xFF);
            }
			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
			printk(KERN_DEBUG "DMI: %s\n", dmi_ids_string);
            return 0;
        }
    }

    return 1;
}

void __init dmi_scan_machine(void)
{
    char __iomem *p, *q;
	char buf[32];



    p = (char*)0x800F0000;

    /*
     * Iterate over all possible DMI header addresses q.
     * Maintain the 32 bytes around q in buf.  On the
     * first iteration, substitute zero for the
     * out-of-range bytes so there is no chance of falsely
     * detecting an SMBIOS header.
     */
    memset(buf, 0, 16);
    for (q = p; q < p + 0x10000; q += 16) {
        memcpy(buf + 16, q, 16);
        if (!dmi_present(buf)) {
            dmi_available = 1;
            goto out;
        }
        memcpy(buf, buf + 16, 16);
    }
 error:
    pr_info("DMI not present or invalid.\n");
 out:
    dmi_initialized = 1;
}

/**
/**
 *	dmi_matches - check if dmi_system_id structure matches system DMI data
 *	@dmi: pointer to the dmi_system_id structure to check
 */
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]) {
			if (!dmi->matches[i].exact_match &&
			    strstr(dmi_ident[s], dmi->matches[i].substr))
				continue;
			else if (dmi->matches[i].exact_match &&
				 !strcmp(dmi_ident[s], dmi->matches[i].substr))
				continue;
		}

		/* No match */
		return false;
	}
	return true;
}

/**
 *	dmi_is_end_of_table - check for end-of-table marker
 *	@dmi: pointer to the dmi_system_id structure to check
 */
static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
{
	return dmi->matches[0].slot == DMI_NONE;
}

/**
 *	dmi_check_system - check system DMI data
 *	@list: array of dmi_system_id structures to match against
 *		All non-null elements of the list must match
 *		their slot's (field index's) data (i.e., each
 *		list string must be a substring of the specified
 *		DMI slot's string data) to be considered a
 *		successful match.
 *
 *	Walk the blacklist table running matching functions until someone
 *	returns non zero or we hit the end. Callback function is called for
 *	each successful match. Returns the number of matches.
 */
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);

/**
 *  dmi_get_system_info - return DMI data value
 *  @field: data index (see enum dmi_field)
 *
 *  Returns one DMI data value, can be used to perform
 *  complex DMI data checks.
 */
const char *dmi_get_system_info(int field)
{
    return dmi_ident[field];
}
EXPORT_SYMBOL(dmi_get_system_info);
/**
 *	dmi_find_device - find onboard device by type/name
 *	@type: device type or %DMI_DEV_TYPE_ANY to match all device types
 *	@name: device name string or %NULL to match all
 *	@from: previous device found in search, or %NULL for new search.
 *
 *	Iterates through the list of known onboard devices. If a device is
 *	found with a matching @vendor and @device, a pointer to its device
 *	structure is returned.  Otherwise, %NULL is returned.
 *	A new search is initiated by passing %NULL as the @from argument.
 *	If @from is not %NULL, searches continue from next device.
 */
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);