linux/drivers/firmware/dmi_scan.c
Lennart Poettering 4f5c791a85 DMI-based module autoloading
The patch below adds DMI/SMBIOS based module autoloading to the Linux
kernel. The idea is to load laptop drivers automatically (and other
drivers which cannot be autoloaded otherwise), based on the DMI system
identification information of the BIOS.

Right now most distros manually try to load all available laptop
drivers on bootup in the hope that at least one of them loads
successfully. This patch does away with all that, and uses udev to
automatically load matching drivers on the right machines.

Basically the patch just exports the DMI information that has been
parsed by the kernel anyway to userspace via a sysfs device
/sys/class/dmi/id and makes sure that proper modalias attributes are
available. Besides adding the "modalias" attribute it also adds
attributes for a few other DMI fields which might be useful for
writing udev rules.

This patch is not an attempt to export the entire DMI/SMBIOS data to
userspace. We already have "dmidecode" which parses the complete DMI
info from userspace. The purpose of this patch is machine model
identification and good udev integration.

To take advantage of DMI based module autoloading, a driver should
export one or more MODULE_ALIAS fields similar to these:

MODULE_ALIAS("dmi:*:svnMICRO-STARINT'LCO.,LTD:pnMS-1013:pvr0131*:cvnMICRO-STARINT'LCO.,LTD:ct10:*");
MODULE_ALIAS("dmi:*:svnMicro-StarInternational:pnMS-1058:pvr0581:rvnMSI:rnMS-1058:*:ct10:*");
MODULE_ALIAS("dmi:*:svnMicro-StarInternational:pnMS-1412:*:rvnMSI:rnMS-1412:*:cvnMICRO-STARINT'LCO.,LTD:ct10:*");
MODULE_ALIAS("dmi:*:svnNOTEBOOK:pnSAM2000:pvr0131*:cvnMICRO-STARINT'LCO.,LTD:ct10:*");

These lines are specific to my msi-laptop.c driver. They are basically
just a concatenation of a few carefully selected DMI fields with all
potentially bad characters stripped.

Besides laptop drivers, modules like "hdaps", the i2c modules
and the hwmon modules are good candidates for "dmi:" MODULE_ALIAS
lines.

Besides merely exporting the DMI data via sysfs the patch adds
support for a few more DMI fields. Especially the CHASSIS fields are
very useful to identify different laptop modules. The patch also adds
working MODULE_ALIAS lines to my msi-laptop.c driver.

I'd like to thank Kay Sievers for helping me to clean up this patch
for posting it on lkml.

Patch is against Linus' current GIT HEAD. Should probably apply to
older kernels as well without modification.


Signed-off-by: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11 16:09:00 -07:00

467 lines
11 KiB
C

#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <asm/dmi.h>
static char * __init dmi_string(struct dmi_header *dm, u8 s)
{
u8 *bp = ((u8 *) dm) + dm->length;
char *str = "";
if (s) {
s--;
while (s > 0 && *bp) {
bp += strlen(bp) + 1;
s--;
}
if (*bp != 0) {
str = dmi_alloc(strlen(bp) + 1);
if (str != NULL)
strcpy(str, bp);
else
printk(KERN_ERR "dmi_string: out of memory.\n");
}
}
return str;
}
/*
* We have to be cautious here. We have seen BIOSes with DMI pointers
* pointing to completely the wrong place for example
*/
static int __init dmi_table(u32 base, int len, int num,
void (*decode)(struct dmi_header *))
{
u8 *buf, *data;
int i = 0;
buf = dmi_ioremap(base, len);
if (buf == NULL)
return -1;
data = buf;
/*
* 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) {
struct dmi_header *dm = (struct dmi_header *)data;
/*
* We want to know the total length (formated 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);
data += 2;
i++;
}
dmi_iounmap(buf, len);
return 0;
}
static int __init dmi_checksum(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(struct dmi_header *dm, int slot, int string)
{
char *p, *d = (char*) dm;
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(struct dmi_header *dm, int slot, int index)
{
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,
"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
dmi_ident[slot] = s;
}
static void __init dmi_save_type(struct dmi_header *dm, int slot, int index)
{
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_devices(struct dmi_header *dm)
{
int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
struct dmi_device *dev;
for (i = 0; i < count; i++) {
char *d = (char *)(dm + 1) + (i * 2);
/* Skip disabled device */
if ((*d & 0x80) == 0)
continue;
dev = dmi_alloc(sizeof(*dev));
if (!dev) {
printk(KERN_ERR "dmi_save_devices: out of memory.\n");
break;
}
dev->type = *d++ & 0x7f;
dev->name = dmi_string(dm, *d);
dev->device_data = NULL;
list_add(&dev->list, &dmi_devices);
}
}
static void __init dmi_save_oem_strings_devices(struct dmi_header *dm)
{
int i, count = *(u8 *)(dm + 1);
struct dmi_device *dev;
for (i = 1; i <= count; i++) {
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 = dmi_string(dm, i);
dev->device_data = NULL;
list_add(&dev->list, &dmi_devices);
}
}
static void __init dmi_save_ipmi_device(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(&dev->list, &dmi_devices);
}
/*
* 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(struct dmi_header *dm)
{
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);
}
}
static int __init dmi_present(char __iomem *p)
{
u8 buf[15];
memcpy_fromio(buf, p, 15);
if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
u16 num = (buf[13] << 8) | buf[12];
u16 len = (buf[7] << 8) | buf[6];
u32 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_table(base,len, num, dmi_decode) == 0)
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 out;
/* 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 out;
rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
dmi_iounmap(p, 32);
if (!rc) {
dmi_available = 1;
return;
}
}
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 out;
for (q = p; q < p + 0x10000; q += 16) {
rc = dmi_present(q);
if (!rc) {
dmi_available = 1;
return;
}
}
}
out: printk(KERN_INFO "DMI not present or invalid.\n");
}
/**
* 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(struct dmi_system_id *list)
{
int i, count = 0;
struct dmi_system_id *d = list;
while (d->ident) {
for (i = 0; i < ARRAY_SIZE(d->matches); i++) {
int s = d->matches[i].slot;
if (s == DMI_NONE)
continue;
if (dmi_ident[s] && strstr(dmi_ident[s], d->matches[i].substr))
continue;
/* No match */
goto fail;
}
count++;
if (d->callback && d->callback(d))
break;
fail: d++;
}
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.
*/
char *dmi_get_system_info(int field)
{
return dmi_ident[field];
}
EXPORT_SYMBOL(dmi_get_system_info);
/**
* dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.
* @str: Case sensitive Name
*/
int dmi_name_in_vendors(char *str)
{
static int fields[] = { DMI_BIOS_VENDOR, DMI_BIOS_VERSION, DMI_SYS_VENDOR,
DMI_PRODUCT_NAME, DMI_PRODUCT_VERSION, DMI_BOARD_VENDOR,
DMI_BOARD_NAME, DMI_BOARD_VERSION, 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);
/**
* 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.
*/
struct dmi_device * dmi_find_device(int type, const char *name,
struct dmi_device *from)
{
struct list_head *d, *head = from ? &from->list : &dmi_devices;
for(d = head->next; d != &dmi_devices; d = d->next) {
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);
/**
* dmi_get_year - Return year of a DMI date
* @field: data index (like dmi_get_system_info)
*
* Returns -1 when the field doesn't exist. 0 when it is broken.
*/
int dmi_get_year(int field)
{
int year;
char *s = dmi_get_system_info(field);
if (!s)
return -1;
if (*s == '\0')
return 0;
s = strrchr(s, '/');
if (!s)
return 0;
s += 1;
year = simple_strtoul(s, NULL, 0);
if (year && year < 100) { /* 2-digit year */
year += 1900;
if (year < 1996) /* no dates < spec 1.0 */
year += 100;
}
return year;
}