Ensure that if nfs_wait_on_sequence() causes our rpc task to wait for
an NFSv4 state serialisation lock, then we also drop the session slot.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

If the server reboots after it has replied to our OPEN, but before we
call nfs4_opendata_to_nfs4_state(), then the reboot recovery thread
will not see a stateid for this open, and so will fail to recover it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Add a mutex to the struct nfs4_state_owner to ensure that delegation
recall doesn't conflict with byte range lock removal.

Note that we nest the new mutex _outside_ the state manager reclaim
protection (nfsi->rwsem) in order to avoid deadlocks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Adjust the return values so that they return EAGAIN to the caller in
cases where we might want to retry the delegation recall after
the state recovery has run.
Note that we can't wait and retry in this routine, because the caller
may be the state manager thread.

If delegation recall fails due to a session or reboot related issue,
also ensure that we mark the stateid as delegated so that
nfs_delegation_claim_opens can find it again later.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

If the server reboots while we are converting a delegation into
OPEN/LOCK stateids as part of a delegation return, the current code
will simply exit with an error. This causes us to lose both
delegation state and locking state (i.e. locking atomicity).

Deal with this by exposing the delegation stateid during delegation
return, so that we can recover the delegation, and then resume
open/lock recovery.

Note that not having to hold the nfs_inode->rwsem across the
calls to nfs_delegation_claim_opens() also fixes a deadlock against
the NFSv4.1 reboot recovery code.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

We currently have a deadlock in which the state recovery thread
ends up blocking due to one of the locks which it is trying to
recover holding the nfs_inode->rwsem.
The situation is as follows: the state recovery thread is
scheduled in order to recover from a reboot. It immediately
drains the session, forcing all ordinary NFSv4.1 calls to
nfs41_setup_sequence() to be put to sleep.  This includes the
file locking process that holds the nfs_inode->rwsem.
When the thread gets to nfs4_reclaim_locks(), it tries to
grab a write lock on nfs_inode->rwsem, and boom...

Fix is to have the lock drop the nfs_inode->rwsem while it is
doing RPC calls. We use a sequence lock in order to signal to
the locking process whether or not a state recovery thread has
run on that inode, in which case it should retry the lock.
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This patch adds a seqcount_t lock for use by the state manager to
signal that an open owner has been recovered. This mechanism will be
used by the delegation, open and byte range lock code in order to
figure out if they need to replay requests due to collisions with
lock recovery.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Ditto for _gss_mech_get_by_pseudoflavor.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This reverts commit 324d003b.

The deadlock turned out to be caused by a workqueue limitation that has
now been worked around in the RPC code (see comment in rpc_free_task).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

It is no longer in use
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Avoid an RCU dereference by removing task->tk_xprt
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Avoid access to task->tk_xprt
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Avoid another RCU dereference by passing the pointer to struct rpc_xprt
from the caller.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

tk_xprt is just a shortcut for tk_client->cl_xprt, however cl_xprt is
defined as an __rcu variable. Replace dereferences of tk_xprt with
non-rcu dereferences where it is safe to do so.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Pull more device-mapper fixes from Alasdair G Kergon:
 "A fix for stacked dm thin devices and a fix for the new dm WRITE SAME
  support."

* tag 'dm-3.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm: fix write same requests counting
  dm thin: fix queue limits stacking

PullHID fixes from Jiri Kosina:

 - fix i2c-hid and hidraw interaction, by Benjamin Tissoires

 - a quirk to make a particular device (Formosa IR receiver) work
   properly, by Nicholas Santos

* 'for-3.8/upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: i2c-hid: fix i2c_hid_output_raw_report
  HID: usbhid: quirk for Formosa IR receiver
  HID: remove x bit from sensor doc

Pull NFS client bugfixes from Trond Myklebust:

 - Error reporting in nfs_xdev_mount incorrectly maps all errors to
   ENOMEM

 - Fix an NFSv4 refcounting issue

 - Fix a mount failure when the server reboots during NFSv4 trunking
   discovery

 - NFSv4.1 mounts may need to run the lease recovery thread.

 - Don't silently fail setattr() requests on mountpoints

 - Fix a SUNRPC socket/transport livelock and priority queue issue

 - We must handle NFS4ERR_DELAY when resetting the NFSv4.1 session.

* tag 'nfs-for-3.8-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4.1: Handle NFS4ERR_DELAY when resetting the NFSv4.1 session
  SUNRPC: When changing the queue priority, ensure that we change the owner
  NFS: Don't silently fail setattr() requests on mountpoints
  NFSv4.1: Ensure that nfs41_walk_client_list() does start lease recovery
  NFSv4: Fix NFSv4 trunking discovery
  NFSv4: Fix NFSv4 reference counting for trunked sessions
  NFS: Fix error reporting in nfs_xdev_mount

Pull MIPS updates from Ralf Baechle:
 "A number of fixes all across the MIPS tree.  No area is particularly
  standing out and things have cooled down quite nicely for a release."

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: Function tracer: Fix broken function tracing
  mips: Move __virt_addr_valid() to a place for MIPS 64
  MIPS: Netlogic: Fix UP compilation on XLR
  MIPS: AR71xx: Fix AR71XX_PCI_MEM_SIZE
  MIPS: AR724x: Fix AR724X_PCI_MEM_SIZE
  MIPS: Lantiq: Fix cp0_perfcount_irq mapping
  MIPS: DSP: Fix DSP mask for registers.
  MIPS: Fix build failure by adding definition of pfn_pmd().
  MIPS: Octeon: Fix warning.
  MIPS: delay.c: Check BITS_PER_LONG instead of __SIZEOF_LONG__
  MIPS: PNX833x: Fix comment.
  MIPS: Add struct p_format to union mips_instruction.
  MIPS: Export <asm/break.h>.
  MIPS: BCM47xx: Enable SSB prerequisite SSB_DRIVER_PCICORE.
  MIPS: BCM47xx: Select GPIOLIB for BCMA on bcm47xx platform
  MIPS: vpe.c: Fix null pointer dereference in print arguments.

i2c_hid_output_raw_report is used by hidraw to forward set_report requests.
The current implementation of i2c_hid_set_report needs to take the
report_id as an argument. The report_id is stored in the first byte
of the buffer in argument of i2c_hid_output_raw_report.

Not removing the report_id from the given buffer adds this byte 2 times
in the command, leading to a non working command.
Reported-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Function tracing is currently broken for all 32 bit MIPS platforms.
When tracing is enabled, the kernel immediately hangs on boot.
This is a result of commit b732d439
that changes the kernel/trace/Kconfig file so that is no longer
forces FRAME_POINTER when FUNCTION_TRACING is enabled.

MIPS frame pointers are generally considered to be useless because
they cannot be used to unwind the stack. Unfortunately the MIPS
function tracing code has bugs that are masked by the use of frame
pointers. This commit fixes the bugs so that MIPS frame pointers
don't need to be enabled.

The bugs are a result of the odd calling sequence used to call the trace
routine. This calling sequence is inserted into every traceable function
when the tracing CONFIG option is enabled. This sequence is generated
for 32bit MIPS platforms by the compiler via the "-pg" flag.

Part of the sequence is "addiu sp,sp,-8" in the delay slot after every
call to the trace routine "_mcount" (some legacy thing where 2 arguments
used to be pushed on the stack). The _mcount routine is expected to
adjust the sp by +8 before returning.  So when not disabled, the original
jalr and addiu will be there, so _mcount has to adjust sp.

The problem is that when tracing is disabled for a function, the
"jalr _mcount" instruction is replaced with a nop, but the
"addiu sp,sp,-8" is still executed and the stack pointer is left
trashed. When frame pointers are enabled the problem is masked
because any access to the stack is done through the frame
pointer and the stack pointer is restored from the frame pointer when
the function returns.

This patch writes two nops starting at the address of the "jalr _mcount"
instruction whenever tracing is disabled. This means that the
"addiu sp,sp.-8" will be converted to a nop along with the "jalr".  When
disabled, there will be two nops.

This is SMP safe because the first time this happens is during
ftrace_init() which is before any other processor has been started.
Subsequent calls to enable/disable tracing when other CPUs ARE running
will still be safe because the enable will only change the first nop
to a "jalr" and the disable, while writing 2 nops, will only be changing
the "jalr". This patch also stops using stop_machine() to call the
tracer enable/disable routines and calls them directly because the
routines are SMP safe.

When the kernel first boots we have to be able to handle the gcc
generated jalr, addui sequence until ftrace_init gets a chance to run
and change the sequence. At this point mcount just adjusts the stack
and returns. When ftrace_init runs, we convert the jalr/addui to nops.
Then whenever tracing is enabled we convert the first nop to a "jalr
mcount+8". The mcount+8 entry point skips the stack adjust.

[ralf@linux-mips.org: Folded in  Steven Rostedt's build fix.]
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Cc: rostedt@goodmis.org
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4806/
Patchwork: https://patchwork.linux-mips.org/patch/4841/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

When processing write same requests, fix dm to send the configured
number of WRITE SAME requests to the target rather than the number of
discards, which is not always the same.

Device-mapper WRITE SAME support was introduced by commit
23508a96 ("dm: add WRITE SAME support").
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>

Commit d3ce8843 "MIPS: Fix modpost error in modules attepting to use
virt_addr_valid()" moved __virt_addr_valid() from a macro in a header
file to a function in ioremap.c. But ioremap.c is only compiled for MIPS
32, and not for MIPS 64.

When compiling for my yeeloong2, which supposedly supports hibernation,
which compiles kernel/power/snapshot.c which calls virt_addr_valid(), I
got this error:

  LD      init/built-in.o
kernel/built-in.o: In function `memory_bm_free':
snapshot.c:(.text+0x4c9c4): undefined reference to `__virt_addr_valid'
snapshot.c:(.text+0x4ca58): undefined reference to `__virt_addr_valid'
kernel/built-in.o: In function `snapshot_write_next':
(.text+0x4e44c): undefined reference to `__virt_addr_valid'
kernel/built-in.o: In function `snapshot_write_next':
(.text+0x4e890): undefined reference to `__virt_addr_valid'
make[1]: *** [vmlinux] Error 1
make: *** [sub-make] Error 2

I suspect that __virt_addr_valid() is fine for mips 64. I moved it to
mmap.c such that it gets compiled for mips 64 and 32.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4842/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

thin_io_hints() is blindly copying the queue limits from the thin-pool
which can lead to incorrect limits being set.  The fix here simply
deletes the thin_io_hints() hook which leaves the existing stacking
infrastructure to set the limits correctly.

When a thin-pool uses an MD device for the data device a thin device
from the thin-pool must respect MD's constraints about disallowing a bio
from spanning multiple chunks.  Otherwise we can see problems.  If the raid0
chunksize is 1152K and thin-pool chunksize is 256K I see the following
md/raid0 error (with extra debug tracing added to thin_endio) when
mkfs.xfs is executed against the thin device:

md/raid0:md99: make_request bug: can't convert block across chunks or bigger than 1152k 6688 127
device-mapper: thin: bio sector=2080 err=-5 bi_size=130560 bi_rw=17 bi_vcnt=32 bi_idx=0

This extra DM debugging shows that the failing bio is spanning across
the first and second logical 1152K chunk (sector 2080 + 255 takes the
bio beyond the first chunk's boundary of sector 2304).  So the bio
splitting that DM is doing clearly isn't respecting the MD limits.

max_hw_sectors_kb is 127 for both the thin-pool and thin device
(queue_max_hw_sectors returns 255 so we'll excuse sysfs's lack of
precision).  So this explains why bi_size is 130560.

But the thin device's max_hw_sectors_kb should be 4 (PAGE_SIZE) given
that it doesn't have a .merge function (for bio_add_page to consult
indirectly via dm_merge_bvec) yet the thin-pool does sit above an MD
device that has a compulsory merge_bvec_fn.  This scenario is exactly
why DM must resort to sending single PAGE_SIZE bios to the underlying
layer. Some additional context for this is available in the header for
commit 8cbeb67a ("dm: avoid unsupported spanning of md stripe boundaries").

Long story short, the reason a thin device doesn't properly get
configured to have a max_hw_sectors_kb of 4 (PAGE_SIZE) is that
thin_io_hints() is blindly copying the queue limits from the thin-pool
device directly to the thin device's queue limits.

Fix this by eliminating thin_io_hints.  Doing so is safe because the
block layer's queue limits stacking already enables the upper level thin
device to inherit the thin-pool device's discard and minimum_io_size and
optimal_io_size limits that get set in pool_io_hints.  But avoiding the
queue limits copy allows the thin and thin-pool limits to be different
where it is important, namely max_hw_sectors_kb.
Reported-by: Daniel Browning <db@kavod.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

Pull x86 EFI fixes from Peter Anvin:
 "This is a collection of fixes for the EFI support.  The controversial
  bit here is a set of patches which bumps the boot protocol version as
  part of fixing some serious problems with the EFI handover protocol,
  used when booting under EFI using a bootloader as opposed to directly
  from EFI.  These changes should also make it a lot saner to support
  cross-mode 32/64-bit EFI booting in the future.  Getting these changes
  into 3.8 means we avoid presenting an inconsistent ABI to bootloaders.

  Other changes are display detection and fixing efivarfs."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: remove attribute check from setup_efi_pci
  x86, build: Dynamically find entry points in compressed startup code
  x86, efi: Fix PCI ROM handing in EFI boot stub, in 32-bit mode
  x86, efi: Fix 32-bit EFI handover protocol entry point
  x86, efi: Fix display detection in EFI boot stub
  x86, boot: Define the 2.12 bzImage boot protocol
  x86/boot: Fix minor fd leakage in tools/relocs.c
  x86, efi: Set runtime_version to the EFI spec revision
  x86, efi: fix 32-bit warnings in setup_efi_pci()
  efivarfs: Delete dentry from dcache in efivarfs_file_write()
  efivarfs: Never return ENOENT from firmware
  efi, x86: Pass a proper identity mapping in efi_call_phys_prelog
  efivarfs: Drop link count of the right inode

Pull x86 fixes from Peter Anvin:
 "This is a collection of miscellaneous fixes, the most important one is
  the fix for the Samsung laptop bricking issue (auto-blacklisting the
  samsung-laptop driver); the efi_enabled() changes you see below are
  prerequisites for that fix.

  The other issues fixed are booting on OLPC XO-1.5, an UV fix, NMI
  debugging, and requiring CAP_SYS_RAWIO for MSR references, just as
  with I/O port references."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  samsung-laptop: Disable on EFI hardware
  efi: Make 'efi_enabled' a function to query EFI facilities
  smp: Fix SMP function call empty cpu mask race
  x86/msr: Add capabilities check
  x86/dma-debug: Bump PREALLOC_DMA_DEBUG_ENTRIES
  x86/olpc: Fix olpc-xo1-sci.c build errors
  arch/x86/platform/uv: Fix incorrect tlb flush all issue
  x86-64: Fix unwind annotations in recent NMI changes
  x86-32: Start out cr0 clean, disable paging before modifying cr3/4

Pull console lockdep checking revert from Dave Airlie.

The lockdep splat this showed was interesting, but it's very very old,
and we won't be fixing it until 3.9.  In the meantime, undo the lockdep
annotation so that we don't generate the (known) console lockdep issue,
and then possibly hide any potential other (unknown) lockdep problems
that got disabled by the first one that triggered.

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  Revert "console: implement lockdep support for console_lock"

This reverts commit daee7797.

I'll requeue this after the console locking fixes, so lockdep
is useful again for people until fbcon is fixed.
Signed-off-by: Dave Airlie <airlied@redhat.com>

NFS4ERR_DELAY is a legal reply when we call DESTROY_SESSION. It
usually means that the server is busy handling an unfinished RPC
request. Just sleep for a second and then retry.
We also need to be able to handle the NFS4ERR_BACK_CHAN_BUSY return
value. If the NFS server has outstanding callbacks, we just want to
similarly sleep & retry.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

This fixes a livelock in the xprt->sending queue where we end up never
making progress on lower priority tasks because sleep_on_priority()
keeps adding new tasks with the same owner to the head of the queue,
and priority bumps mean that we keep resetting the queue->owner to
whatever task is at the head of the queue.

Regression introduced by commit c05eecf6
(SUNRPC: Don't allow low priority tasks to pre-empt higher priority ones).
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Various urgent EFI fixes and some warning cleanups for v3.8

  * EFI boot stub fix for Macbook Pro's from Maarten Lankhorst
  * Fix an oops in efivarfs from Lingzhu Xiang
  * 32-bit warning cleanups from Jan Beulich
  * Patch to Boot on >512GB RAM systems from Nathan Zimmer
  * Set efi.runtime_version correctly
  * efivarfs updates
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Ensure that any setattr and getattr requests for junctions and/or
mountpoints are sent to the server. Ever since commit
0ec26fd0 (vfs: automount should ignore LOOKUP_FOLLOW), we have
silently dropped any setattr requests to a server-side mountpoint.
For referrals, we have silently dropped both getattr and setattr
requests.

This patch restores the original behaviour for setattr on mountpoints,
and tries to do the same for referrals, provided that we have a
filehandle...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

The commit 2a37b1ae "MIPS: Netlogic: Move from u32 cpumask to cpumask_t"
breaks uniprocessor compilation on XLR with:

arch/mips/netlogic/xlr/setup.c: In function 'prom_init':
arch/mips/netlogic/xlr/setup.c:196:6: error: unused variable 'i'

Fix by defining 'i' only when CONFIG_SMP is defined.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4760/Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The base address of the PCI memory is 0x10000000 and the base address of the
PCI configuration space is 0x17000000 on the AR71xx SoCs.

The AR71XX_PCI_MEM_SIZE is defined as 0x08000000 which is wrong because that
overlaps with the configuration space.  This patch fixes the value of the
AR71XX_PCI_MEM_SIZE constant, in order to avoid this resource conflicts.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4873/Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The base address of the PCI memory is
0x10000000 and the base address of the
PCI configuration space is 0x14000000
on the AR724x SoCs.

The AR724X_PCI_MEM_SIZE is defined as
0x08000000 which is wrong because that
overlaps  with the configuration space.

The patch fixes the value of the
AR724X_PCI_MEM_SIZE constant, in order
to avoid this resource conflicts.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4872/Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The introduction of the OF support broke the cp0_perfcount_irq mapping. This
resulted in oprofile not working anymore.

Offending commit is :

commit 3645da02
Author: John Crispin <blogic@openwrt.org>
Date:   Tue Apr 17 10:18:32 2012 +0200

OF: MIPS: lantiq: implement irq_domain support
Signed-off-by: Conor O'Gorman <i@conorogorman.net>
Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4875/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

It has been reported that running this driver on some Samsung laptops
with EFI can cause those machines to become bricked as detailed in the
following report,

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

There have also been reports of this driver causing Machine Check
Exceptions on recent EFI-enabled Samsung laptops,

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

So disable it if booting from EFI since this driver relies on
grovelling around in the BIOS memory map which isn't going to work.

Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

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>