path: root/drivers/firmware/dmi_scan.c

#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 <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);

	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)