linux/drivers/firmware/dmi_scan.c
Rafael J. Wysocki d7b1956fed DMI: Introduce dmi_first_match to make the interface more flexible
Some notebooks from HP have the problem that their BIOSes attempt to
spin down hard drives before entering ACPI system states S4 and S5.
This leads to a yo-yo effect during system power-off shutdown and the
last phase of hibernation when the disk is first spun down by the
kernel and then almost immediately turned on and off by the BIOS.
This, in turn, may result in shortening the disk's life times.

To prevent this from happening we can blacklist the affected systems
using DMI information.  However, only the on-board controlles should
be blacklisted and their PCI slot numbers can be used for this
purpose.  Unfortunately the existing interface for checking DMI
information of the system is not very convenient for this purpose,
because to use it, we would have to define special callback functions
or create a separate struct dmi_system_id table for each blacklisted
system.

To overcome this difficulty introduce a new function
dmi_first_match() returning a pointer to the first entry in an array
of struct dmi_system_id elements that matches the system DMI
information.  Then, we can use this pointer to access the entry's
.driver_data field containing the additional information, such as
the PCI slot number, allowing us to do the desired blacklisting.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-01-27 02:15:47 -05:00

638 lines
15 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>
/*
* 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 *))
{
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);
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 *))
{
u8 *buf;
buf = dmi_ioremap(dmi_base, dmi_len);
if (buf == NULL)
return -1;
dmi_table(buf, dmi_len, dmi_num, decode);
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,
"%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(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_extended_devices(const struct dmi_header *dm)
{
const u8 *d = (u8*) dm + 5;
/* Skip disabled device */
if ((*d & 0x80) == 0)
return;
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)
{
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 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)
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;
}
/**
* 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)
continue;
if (dmi_ident[s]
&& strstr(dmi_ident[s], dmi->matches[i].substr))
continue;
/* No match */
return false;
}
return true;
}
/**
* 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; d->ident; d++)
if (dmi_matches(d)) {
count++;
if (d->callback && d->callback(d))
break;
}
return count;
}
EXPORT_SYMBOL(dmi_check_system);
/**
* dmi_first_match - find dmi_system_id structure matching 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 until the first match is found. Return the
* pointer to the matching entry or NULL if there's no match.
*/
const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
{
const struct dmi_system_id *d;
for (d = list; d->ident; d++)
if (dmi_matches(d))
return d;
return NULL;
}
EXPORT_SYMBOL(dmi_first_match);
/**
* 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_name_in_serial - Check if string is in the DMI product serial information
* @str: string to check for
*/
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;
}
/**
* dmi_name_in_vendors - Check if string is anywhere in the DMI vendor information.
* @str: Case sensitive Name
*/
int dmi_name_in_vendors(const 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.
*/
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);
/**
* 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;
const 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;
}
/**
* dmi_walk - Walk the DMI table and get called back for every record
* @decode: Callback function
*
* Returns -1 when the DMI table can't be reached, 0 on success.
*/
int dmi_walk(void (*decode)(const struct dmi_header *))
{
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);
iounmap(buf);
return 0;
}
EXPORT_SYMBOL_GPL(dmi_walk);
/**
* dmi_match - compare a string to the dmi field (if exists)
* @f: DMI field identifier
* @str: string to compare the DMI field to
*
* Returns true if the requested field equals to the str (including NULL).
*/
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);