linux/drivers/firmware/dmi_scan.c
Matt Fleming 83e6818974 efi: Make 'efi_enabled' a function to query EFI facilities
Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.

The immediate motivation for this patch is the bug report at,

    https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557

which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,

    https://bugzilla.kernel.org/show_bug.cgi?id=47121

details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,

    if (!efi_enabled)

hasn't been a sufficient condition for quite some time.

Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.

For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).

This patch is a prereq for the samsung-laptop fix patch.

Cc: David Airlie <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-30 11:51:59 -08:00

797 lines
18 KiB
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 <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[] = " ";
static u16 __initdata dmi_ver;
/*
* 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 len)
{
u8 sum = 0;
int a;
for (a = 0; a < len; 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_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) {
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 (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 (dmi_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_dump_ids();
return 0;
}
}
dmi_ver = 0;
return 1;
}
static int __init smbios_present(const char __iomem *p)
{
u8 buf[32];
int offset = 0;
memcpy_fromio(buf, p, 32);
if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) {
dmi_ver = (buf[6] << 8) + buf[7];
/* Some BIOS report weird SMBIOS version, fix that up */
switch (dmi_ver) {
case 0x021F:
case 0x0221:
pr_debug("SMBIOS version fixup(2.%d->2.%d)\n",
dmi_ver & 0xFF, 3);
dmi_ver = 0x0203;
break;
case 0x0233:
pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6);
dmi_ver = 0x0206;
break;
}
offset = 16;
}
return dmi_present(buf + offset);
}
void __init dmi_scan_machine(void)
{
char __iomem *p, *q;
int rc;
if (efi_enabled(EFI_CONFIG_TABLES)) {
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 = smbios_present(p);
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) {
if (memcmp(q, "_SM_", 4) == 0 && q - p <= 0xFFE0)
rc = smbios_present(q);
else if (memcmp(q, "_DMI_", 5) == 0)
rc = dmi_present(q);
else
continue;
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)
break;
if (dmi_ident[s]
&& strstr(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_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; !dmi_is_end_of_table(d); 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 in the DMI system or board vendor name
* @str: Case sensitive Name
*/
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);
/**
* 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_date - parse a DMI date
* @field: data index (see enum dmi_field)
* @yearp: optional out parameter for the year
* @monthp: optional out parameter for the month
* @dayp: optional out parameter for the day
*
* The date field is assumed to be in the form resembling
* [mm[/dd]]/yy[yy] and the result is stored in the out
* parameters any or all of which can be omitted.
*
* If the field doesn't exist, all out parameters are set to zero
* and false is returned. Otherwise, true is returned with any
* invalid part of date set to zero.
*
* On return, year, month and day are guaranteed to be in the
* range of [0,9999], [0,12] and [0,31] respectively.
*/
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);
/**
* dmi_walk - Walk the DMI table and get called back for every record
* @decode: Callback function
* @private_data: Private data to be passed to the callback function
*
* Returns -1 when the DMI table can't be reached, 0 on success.
*/
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);
/**
* 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);