Function dmi_matches can me made a bit faster:

* The documented purpose of dmi_initialized is to catch too early
  calls to dmi_check_system(). I'm not fully convinced it justifies
  slowing down the initialization of all systems out there, but at
  least the check should not have been moved from dmi_check_system()
  to dmi_matches(). dmi_matches() is being called for every entry of
  the table passed to dmi_check_system(), causing the same redundant
  check to be performed again and again. So move it back to
  dmi_check_system(), reverting this specific portion of commit
  d7b1956f ("DMI: Introduce dmi_first_match to make the interface
  more flexible").

* Don't check for the exact_match flag again when we already know its
  value.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Fixes: d7b1956f ("DMI: Introduce dmi_first_match to make the interface more flexible")
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Jeff Garzik <jgarzik@redhat.com>

Before accessing DMI data to record it for later, we should ensure
that the DMI structures are large enough to contain the data in
question.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>

Currently they return -1 on error, which will confuse callers if
they try to interpret it as a normal negative error code.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

Since version 3.0.0 of the SMBIOS specification, there can be
multiple entry points in memory, pointing to one or two DMI tables.
If both a 32-bit ("_SM_") entry point and a 64-bit ("_SM3_") entry
point are present, the specification requires that the latter points
to a table which is a super-set of the table pointed to by the
former. Therefore we should give preference to the 64-bit ("_SM3_")
entry point.

However, currently the code is picking the first valid entry point
it finds. Per specification, we should look for a 64-bit ("_SM3_")
entry point first, and if we can't find any, look for a 32-bit
("_SM_" or "_DMI_") entry point. Modify the code to do that.
Signed-off-by: NJean Delvare <jdelvare@suse.de>

Sometimes it is more convenient to be able to match a whole family of
products, like in case of bunch of Chromebooks based on Intel_Strago to
apply a driver quirk instead of quirking each machine one-by-one.

This adds support for DMI_PRODUCT_FAMILY identification string and also
exports it to the userspace through sysfs attribute just like the
existing ones.
Suggested-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Let's keep consistent when print dmi_ids_string between SMBIOS 2.x
and SMBIOS 3.x, and always show the system identification string,
like Vendor, Product/Board name and BIOS infos.
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

Save SMBIOS Type 9 System Slots during DMI scan. PCI address of
onboard devices was already saved but not for slots.
Signed-off-by: NJordan Hargrave <jordan_hargrave@dell.com>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

The description of dmi_find_device was apparently copied from a
similar function in a different subsystem, but the parameter names
were not adjusted as needed.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Andrey Panin <pazke@donpac.ru>

Get rid of the arbitrary 5-byte pointer offset, it served no purpose
and made it harder to match the code with the SMBIOS specification.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Jordan Hargrave <jordan_hargrave@dell.com>
Cc: Narendra K <narendra_k@dell.com>

Calling dmi_string_nosave isn't cheap, so avoid calling it twice in a
row for the same string.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Jordan Hargrave <jordan_hargrave@dell.com>
Cc: Narendra K <narendra_k@dell.com>

The dmi_ver wasn't updated correctly before the dmi_decode method run
to save the uuid.

That resulted in "dmidecode -s system-uuid" and
/sys/class/dmi/id/product_uuid disagreeing. The latter was buggy and
this fixes it.
Reported-by: NFederico Simoncelli <fsimonce@redhat.com>
Fixes: 9f9c9cbb ("drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists")
Fixes: 79bae42d ("dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()")
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

Signed-off-by: NJean Delvare <jdelvare@suse.de>

Some utils, like dmidecode and smbios, need to access SMBIOS entry
table area in order to get information like SMBIOS version, size, etc.
Currently it's done via /dev/mem. But for situation when /dev/mem
usage is disabled, the utils have to use dmi sysfs instead, which
doesn't represent SMBIOS entry and adds code/delay redundancy when direct
access for table is needed.

So this patch creates dmi/tables and adds SMBIOS entry point to allow
utils in question to work correctly without /dev/mem. Also patch adds
raw dmi table to simplify dmi table processing in user space, as
proposed by Jean Delvare.
Tested-by: NRoy Franz <roy.franz@linaro.org>
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@globallogic.com>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

The SMBIOS v3 entry points specify a maximum length for the DMI table,
not the exact length. Thus there may be garbage after the end-of-table
marker, which we don't want to export to user-space. Adjust dmi_len
when we find the end-of-table marker, so that only the actual table
payload is exported.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@globallogic.com>

The "dmi_table" function looks like data instance, but it does DMI
table decode. This patch renames it to "dmi_decode_table" name as
more appropriate. That allows us to use "dmi_table" name for correct
purposes.
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@globallogic.com>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

A 32-bit entry point to a DMI table says how many structures the table
contains. The SMBIOS specification explicitly says that end-of-table
markers should be ignored if they are not actually at the end of the
DMI table. So only honor the end-of-table marker for tables accessed
through 64-bit entry points, as they do not specify a structure count.

Fixes: fc430262 ("dmi: add support for SMBIOS 3.0 64-bit entry point")
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Matt Fleming <matt.fleming@intel.com>

In function dmi_present(), dmi_walk_early() calls dmi_table(), which
calls dmi_decode(), which ultimately calls dmi_save_uuid(). This last
function makes a decision based on the value of global variable
dmi_ver. The problem is that this variable is set right _after_
dmi_walk_early() returns. So dmi_save_uuid() always sees dmi_ver == 0
regardless of the actual version implemented.

This causes /sys/class/dmi/id/product_uuid to always use the old
ordering even on systems implementing DMI/SMBIOS 2.6 or later, which
should use the new ordering.

This is broken since kernel v3.8 for legacy DMI implementations and
since kernel v3.10 for SMBIOS 2 implementations. SMBIOS 3
implementations with the 64-bit entry point are not affected.

The first breakage does not matter much as in practice legacy DMI
implementations are always for versions older than 2.6, which is when
the UUID ordering changed. The second breakage is more problematic as
it affects the vast majority of x86 systems manufactured since 2009.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Fixes: 9f9c9cbb ("drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists")
Fixes: 79bae42d ("dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()")
Acked-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Artem Savkov <artem.savkov@gmail.com>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: stable@vger.kernel.org [v3.10+]

The trailing .x adds no information for the reader, and if anyone
tries to parse that line, this is more work as they have 3 different
formats to handle instead of 2. Plus, this makes backporting fixes
harder.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Fixes: 95be58df ("firmware: dmi_scan: Use full dmi version for SMBIOS3")
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>

dmi_num is a u16, dmi_len is a u32, so this construct:

	dmi_num = dmi_len / 4;

would result in an integer overflow for a DMI table larger than
256 kB. I've never see such a large table so far, but SMBIOS 3.0
makes it possible so maybe we'll see such tables in the future.

So instead of faking a structure count when the entry point does
not provide it, adjust the loop condition in dmi_table() to properly
deal with the case where dmi_num is not set.

This bug was introduced with the initial SMBIOS 3.0 support in commit
fc430262 ("dmi: add support for SMBIOS 3.0 64-bit entry point").
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: <stable@vger.kernel.org>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

There is no reason to pass static vars to function that can use
only them.

The dmi_table() can use only dmi_len and dmi_num static vars, so use
them directly. In this case we can freely change their type in one
place and slightly decrease redundancy.
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

New SMBIOS3 spec adds additional field for versioning - docrev.
The docrev identifies the revision of a specification implemented in
the table structures, so display SMBIOSv3 versions in format,
like "3.22.1".

In case of only 32 bit entry point for versions > 3 display
dmi version like "3.22.x" as we don't know the docrev.

In other cases display version like it was.
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

According to SMBIOSv3 specification the length of DMI table can be
up to 32bits wide. So use appropriate type to avoid overflow.

It's obvious that dmi_num theoretically can be more than u16 also,
so it's can be changed to u32 or at least it's better to use int
instead of u16, but on that moment I cannot imagine dmi structure
count more than 65535 and it can require changing type of vars that
work with it. So I didn't correct it.
Acked-by: NArd Biesheuvel <ard@linaro.org>
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The dmi-sysfs should create "End of Table" entry, that is type 127. But
after adding initial SMBIOS v3 support fc430262 ("dmi: add support
for SMBIOS 3.0 64-bit entry point") the 127-0 entry is not handled any
more, as result it's not created in dmi sysfs for instance. This is
important because the size of whole DMI table must correspond to sum of
all DMI entry sizes.

So move the end-of-table check after it's handled by dmi_table.
Reviewed-by: NArd Biesheuvel <ard@linaro.org>
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: <stable@vger.kernel.org> # v3.19
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The DMTF SMBIOS reference spec v3.0.0 defines a new 64-bit entry point,
which enables support for SMBIOS structure tables residing at a physical
offset over 4 GB. This is especially important for upcoming arm64
platforms whose system RAM resides entirely above the 4 GB boundary.

For the UEFI case, this code attempts to detect the new SMBIOS 3.0
header magic at the offset passed in the SMBIOS3_TABLE_GUID UEFI
configuration table. If this configuration table is not provided, or
if we fail to parse the header, we fall back to using the legacy
SMBIOS_TABLE_GUID configuration table. This is in line with the spec,
that allows both configuration tables to be provided, but mandates that
they must point to the same structure table, unless the version pointed
to by the 64-bit entry point is a superset of the 32-bit one.

For the non-UEFI case, the detection logic is modified to look for the
SMBIOS 3.0 header magic before it looks for the legacy header magic.

Note that this patch is based on version 3.0.0d [draft] of the
specification, which is expected not to deviate from the final version
in ways that would affect the correctness of this implementation.
Tested-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Acked-by: NLeif Lindholm <leif.lindholm@linaro.org>
Tested-by: NLeif Lindholm <leif.lindholm@linaro.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Acked-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>

This patch makes a couple of changes to the SMBIOS/DMI scanning
code so it can be used on other archs (such as ARM and arm64):
(a) wrap the calls to ioremap()/iounmap(), this allows the use of a
    flavor of ioremap() more suitable for random unaligned access;
(b) allow the non-EFI fallback probe into hardcoded physical address
    0xF0000 to be disabled.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Firmware is not required to maintain alignment of SMBIOS
entries, so we should take care accessing fields within these
structures. Use "get_unaligned()" to avoid problems.

[ Found on ia64 (which grumbles about unaligned access) ]
Signed-off-by: NTony Luck <tony.luck@intel.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/27d82dbff5be1025bf18ab88498632d36c2fcf3c.1383331440.git.tony.luck@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This patch adds a new interface to decode memory device (type 17)
to help error reporting on DIMMs.

Original-author: Tony Luck <tony.luck@intel.com>
Signed-off-by: NChen, Gong <gong.chen@linux.intel.com>
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NMauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

As reported by Joe Perches: OOM messages generally aren't useful.
dmi_alloc is either a trivial front-end to kzalloc, and kzalloc already
does a dump_stack() when OOM, or for x86, dmi_alloc uses extend_brk
which BUGs when unsuccessful.

So we can remove all 6 such log messages in the dmi_scan driver, to
shrink the binary size (by 528 bytes on x86_64.)
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Reported-by: NJoe Perches <joe@perches.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add const to all DMI string pointers where this is possible.  This fixes a
checkpatch warning.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Joe Perches <joe@perches.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix all errors and trivial warnings reported by checkpatch for file
drivers/firmware/dmi_scan.c.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Joe Perches <joe@perches.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This comment predates the introduction of early_ioremap.  Since then the
missing calls to dmi_iounmap have been added by Ingo and Yinghai in
commits 0d64484f ("x86: fix DMI ioremap leak") and 3212bff3
("x86: left over fix for leak of early_ioremp in dmi_scan") .  That was
over 5 years ago so it is about time to drop this now misleading
comment.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

My previous refactoring in commit 79bae42d ("dmi_scan: refactor
dmi_scan_machine(), {smbios,dmi}_present()") resulted in slightly tricky
code (though I think it's more elegant).  Explain what it's doing.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dmi_match() considers a substring match to be a successful match.  This is
not always sufficient to distinguish between DMI data for different
systems.  Add support for exact string matching using strcmp() in addition
to the substring matching using strstr().

The specific use case in the i915 driver is to allow us to use an exact
match for D510MO, without also incorrectly matching D510MOV:

  {
	.ident = "Intel D510MO",
	.matches = {
		DMI_MATCH(DMI_BOARD_VENDOR, "Intel"),
		DMI_EXACT_MATCH(DMI_BOARD_NAME, "D510MO"),
	},
  }
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Cc: <annndddrr@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Cornel Panceac <cpanceac@gmail.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the calls to memcpy_fromio() up into the loop in
dmi_scan_machine(), and move the signature checks back down into
dmi_decode().  We need to check at 16-byte intervals but keep a 32-byte
buffer for an SMBIOS entry, so shift the buffer after each iteration.

Merge smbios_present() into dmi_present(), so we look for an SMBIOS
signature at the beginning of the given buffer and then for a DMI
signature at an offset of 16 bytes.

[artem.savkov@gmail.com: use proper buf type in dmi_present()]
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Reported-by: NTim McGrath <tmhikaru@gmail.com>
Tested-by: NTim Mcgrath <tmhikaru@gmail.com>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: NArtem Savkov <artem.savkov@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

x86 and ia64 can acquire extra hardware identification information
from DMI and print it along with task dumps; however, the usage isn't
consistent.

* x86 show_regs() collects vendor, product and board strings and print
  them out with PID, comm and utsname.  Some of the information is
  printed again later in the same dump.

* warn_slowpath_common() explicitly accesses the DMI board and prints
  it out with "Hardware name:" label.  This applies to both x86 and
  ia64 but is irrelevant on all other archs.

* ia64 doesn't show DMI information on other non-WARN dumps.

This patch introduces arch-specific hardware description used by
dump_stack().  It can be set by calling dump_stack_set_arch_desc()
during boot and, if exists, printed out in a separate line with
"Hardware name:" label.

dmi_set_dump_stack_arch_desc() is added which sets arch-specific
description from DMI data.  It uses dmi_ids_string[] which is set from
dmi_present() used for DMI debug message.  It is superset of the
information x86 show_regs() is using.  The function is called from x86
and ia64 boot code right after dmi_scan_machine().

This makes the explicit DMI handling in warn_slowpath_common()
unnecessary.  Removed.

show_regs() isn't yet converted to use generic debug information
printing and this patch doesn't remove the duplicate DMI handling in
x86 show_regs().  The next patch will unify show_regs() handling and
remove the duplication.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #3
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a08e
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
  [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a0c3>] init_workqueues+0x35/0x505
  ...

v2: Use the same string as the debug message from dmi_present() which
    also contains BIOS information.  Move hardware name into its own
    line as warn_slowpath_common() did.  This change was suggested by
    Bjorn Helgaas.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We're goning to use DMI identification for other purposes too.  Morph
dmi_dump_ids() which is used to print DMI identification as a debug
message during boot into dmi_format_ids() which formats the same
information sans the leading "DMI:" tag into a string buffer.

dmi_present() is updated to format the information into dmi_ids_string[]
using the new function and print it with "DMI:" prefix.

dmi_ids_string[] will be used for another purpose by a future patch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 9f9c9cbb ("drivers/firmware/dmi_scan.c: fetch dmi version
from SMBIOS if it exists") hoisted the check for "_DMI_" into
dmi_scan_machine(), which means that we don't bother to check for
"_DMI_" at offset 16 in an SMBIOS entry.  smbios_present() may also call
dmi_present() for an address where we found "_SM_", if it failed further
validation.

Check for "_DMI_" in smbios_present() before calling dmi_present().

[akpm@linux-foundation.org: fix build]
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Reported-by: NTim McGrath <tmhikaru@gmail.com>
Tested-by: NTim Mcgrath <tmhikaru@gmail.com>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The right dmi version is in SMBIOS if it's zero in DMI region

This issue was originally found from an oracle bug.
One customer noticed system UUID doesn't match between dmidecode & uek2.

 - HP ProLiant BL460c G6 :
   # cat /sys/devices/virtual/dmi/id/product_uuid
   00000000-0000-4C48-3031-4D5030333531
   # dmidecode | grep -i uuid
   UUID: 00000000-0000-484C-3031-4D5030333531

From SMBIOS 2.6 on, spec use little-endian encoding for UUID other than
network byte order.

So we need to get dmi version to distinguish.  If version is 0.0, the
real version is taken from the SMBIOS version.  This is part of original
kernel comment in code.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Feng Jin <joe.jin@oracle.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As of version 2.6 of the SMBIOS specification, the first 3 fields of the
UUID are supposed to be little-endian encoded.

Also a minor fix to match variable meaning and mute checkpatch.pl

[akpm@linux-foundation.org: tweak code comment]
Signed-off-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Feng Jin <joe.jin@oracle.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>