Compile-testing for a 64-bit arch uncovers several bad casts:

    In file included from include/linux/linkage.h:4:0,
                     from include/linux/kernel.h:6,
                     from drivers/mtd/devices/st_spi_fsm.c:15:
    drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_read_fifo’:
    drivers/mtd/devices/st_spi_fsm.c:758:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
      BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
    ...

Use uintptr_t instead of uint32_t, since it's guaranteed to be
pointer-sized.

We also see this warning, if size_t is not 32 bits wide:

    In file included from drivers/mtd/devices/st_spi_fsm.c:15:0:
    drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_mtd_write’:
    include/linux/kernel.h:712:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
      (void) (&_min1 == &_min2);  \
                     ^
    drivers/mtd/devices/st_spi_fsm.c:1704:11: note: in expansion of macro ‘min’
       bytes = min(FLASH_PAGESIZE - page_offs, len);
               ^

Just use min_t() to force the type conversion, since we don't really
want to upgrade 'page_offs' and 'bytes' to size_t; they only should be
handling <= 256 byte offsets.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>

This corrects some sparse warnings:

   drivers/mtd/spi-nor/fsl-quadspi.c:281:31: warning: incorrect type in initializer (different address spaces) [sparse]
   drivers/mtd/spi-nor/fsl-quadspi.c:281:31:    expected void *[noderef] <asn:2>base [sparse]
   drivers/mtd/spi-nor/fsl-quadspi.c:281:31:    got void [noderef] <asn:2>*iobase [sparse]
   (etc.)
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>

There's no reason this can't be a module. Also, give SPI-NOR its own
submenu.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>

Many of the serial_flash_cmds.h opcodes are duplicated with spi-nor.h.
Let's begin to unify them.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>

Begin to unify the differences between serial_flash_cmds.h and
spi-nor.h.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>

These are also in serial_flash_cmds.h. (FWIW, I didn't know the C
preprocessor allowed redefinitions without warning like this.)
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>

I hear that this driver should depend on ARCH_STI, and that "SH" is not
actually a real symbol. At the same time, let's allow compile-testing on
other ARCH'es.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Huang Shijie <b32955@freescale.com>

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>

serial_flash_cmds.h defines our opcodes a little differently. Let's
borrow its naming, since it's borrowed from the SFDP standard, and it's
more extensible.

This prepares us for merging serial_flash_cmds.h and spi-nor.h opcode
listing.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Huang Shijie <b32955@freescale.com>

Qualify these with a better namespace, and prepare them for use in more
drivers.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Huang Shijie <b32955@freescale.com>

Spacing is a little non-standard here. Fix up tabs vs. spaces.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
Reviewed-by: Marek Vasut <marex@denx.de>

Add the copyright information for spi-nor.c and spi-nor.h.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This patch adds support for the Macronix MX25L3255E device.  Unlike the other
Macronix devices we have seen, this device supports WRITE_1_4_4 at reasonable
frequencies.  Rather than masking out WRITE_1_4_4 support altogether, we now
rely on the table parameters to indicate whether or not WRITE_1_4_4 should be
used.
Signed-off-by: Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add Spansion S25FL032P to the list of known devices.
Signed-off-by: Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This patch refactors the fsm_read_status() and fsm_write_status() code to
support 1 or 2 byte operations, with a specified command.  This allows us to
remove device/register specific code, such as the N25Q fsm_wrvcr() function.

The 'QE' configuration code is updated accordingly, with minor tweaks to ensure
the register values are only written if actually required.  One notable change
in this area is that the 'W25Q_STATUS_QE' bit-field is now defined with respect
to the 'SR2' register, rather than the combined 'SR1+SR2' register which is only
used for write operations.
Signed-off-by: Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Update the configuration of the Macronix 'QE' bit, such that
we only set or clear the bit if required.
Signed-off-by: Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Support for the Macronix 32-bit addressing scheme was originally developed using
the MX25L25635E device.  As is often the case, it was found that the presence of
a "WAIT" instruction was required for the "EN4B/EX4B" FSM Sequence to complete.
(It is known that the SPI FSM Controller makes certain undocumented assumptions
regarding what constitutes a valid sequence.)  However, further testing
suggested that a small delay was required after issuing the "EX4B" command;
without this delay, data corruptions were observed, consistent with the device
not being ready to retrieve data.  Although the issue was not fully understood,
the workaround of adding a small delay was implemented, while awaiting
clarification from Macronix.

The same behaviour has now been found with a second Macronix device, the
MX25L25655E.  However, with this device, it seems that the delay is also
required after the 'EN4B' commands.  This discovery has prompted us to revisit
the issue.

Although still not conclusive, further tests have suggested that the issue is
down to the SPI FSM Controller, rather than the Macronix devices.  Furthermore,
an alternative workaround has emerged which is to set the WAIT time to
0x00000001, rather then 0x00000000.  (Note, the WAIT instruction is used purely
for the purpose of achieving "sequence validity", rather than actually
implementing a delay!)

The issue is now being investigated by the Design and Validation teams.  In the
meantime, we implement the alternative workaround, which reduces the effective
delay from 1us to 1ns.
Signed-off-by: Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add Macronix MX25L25655E to the list of known devices.
Signed-off-by: Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix errors like this:

    ERROR: "spi_nor_ids" [drivers/mtd/devices/m25p80.ko] undefined!
    ERROR: "spi_nor_scan" [drivers/mtd/devices/m25p80.ko] undefined!
    make[1]: *** [__modpost] Error 1
    make: *** [modules] Error 2
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

(0) What is the QuadSPI controller?

    The QuadSPI(Quad Serial Peripheral Interface) acts as an interface to
    one single or two external serial flash devices, each with up to 4
    bidirectional data lines.

(1) The QuadSPI controller is driven by the LUT(Look-up Table) registers.
    The LUT registers are a look-up-table for sequences of instructions.
    A valid sequence consists of four LUT registers.

(2) The definition of the LUT register shows below:

    ---------------------------------------------------
    | INSTR1 | PAD1 | OPRND1 | INSTR0 | PAD0 | OPRND0 |
    ---------------------------------------------------

    There are several types of INSTRx, such as:
	CMD	: the SPI NOR command.
	ADDR	: the address for the SPI NOR command.
	DUMMY	: the dummy cycles needed by the SPI NOR command.
	....

    There are several types of PADx, such as:
	PAD1	: use a singe I/O line.
	PAD2	: use two I/O lines.
	PAD4	: use quad I/O lines.
	....

(3) Test this driver with the JFFS2 and UBIFS:

    For jffs2:
    -------------
	#flash_eraseall /dev/mtd0
	#mount -t jffs2 /dev/mtdblock0 tmp
	#bonnie++ -d tmp -u 0 -s 10 -r 5

    For ubifs:
    -------------
	#flash_eraseall /dev/mtd0
	#ubiattach /dev/ubi_ctrl -m 0
	#ubimkvol /dev/ubi0 -N test -m
	#mount -t ubifs ubi0:test tmp
	#bonnie++ -d tmp -u 0 -s 10 -r 5
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This patch adds the binding file for Freescale QuadSPI driver.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add the spi_nor_match_id() to find the proper spi_device_id with the
NOR flash's name in the spi_nor_ids table.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Use the new SPI nor framework, and rewrite the m25p80:
 (0) remove all the NOR comands.
 (1) change the m25p->command to an array.
 (2) implement the necessary hooks, such as m25p80_read/m25p80_write.

Tested with the m25p32.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
[Brian: rebased]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This patch adds the document for the SPI NOR framework.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This patch cloned most of the m25p80.c. In theory, it adds a new spi-nor layer.

Before this patch, the layer is like:

                   MTD
         ------------------------
                  m25p80
         ------------------------
	       spi bus driver
         ------------------------
	        SPI NOR chip

After this patch, the layer is like:
                   MTD
         ------------------------
                  spi-nor
         ------------------------
                  m25p80
         ------------------------
	       spi bus driver
         ------------------------
	       SPI NOR chip

With the spi-nor controller driver(Freescale Quadspi), it looks like:
                   MTD
         ------------------------
                  spi-nor
         ------------------------
                fsl-quadspi
         ------------------------
	       SPI NOR chip

New APIs:
   spi_nor_scan: used to scan a spi-nor flash.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
[Brian: rebased to include additional m25p_ids[] entry]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The spi_nor{} is cloned from the m25p{}.
The spi_nor{} can be used by both the m25p80 and spi-nor controller.

We also add the spi_nor_xfer_cfg{} which can be used by the two
fundamental primitives: read_xfer/write_xfer.

 1) the hooks for spi_nor{}:
    @prepare/unpreare: used to do some work before or after the
             read/write/erase/lock/unlock.
    @read_xfer/write_xfer: We can use these two hooks to code all
             the following hooks if the driver tries to implement them
             by itself.
    @read_reg: used to read the registers, such as read status register,
             read configure register.
    @write_reg: used to write the registers, such as write enable,
             erase sector.
    @read_id: read out the ID info.
    @wait_till_ready: wait till the NOR becomes ready.
    @read: read out the data from the NOR.
    @write: write data to the NOR.
    @erase: erase a sector of the NOR.

 2) Add a new field sst_write_second for the SST NOR write.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This patch adds a new header :spi-nor.h,
and copies all the SPI NOR commands and relative macros into this new header.

This hearder can be used by the m25p80.c and other spi-nor controller,
such as Freescale's Quadspi.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Some versions of gcc even warn about it:

  mm/shmem.c: In function ‘shmem_file_aio_read’:
  mm/shmem.c:1414: warning: ‘error’ may be used uninitialized in this function

If the loop is aborted during the first iteration by one of the two
first break statements, error will be uninitialized.

Introduced by commit 6e58e79d ("introduce copy_page_to_iter, kill
loop over iovec in generic_file_aio_read()").
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On 32 bit, size_t is "unsigned int", not "unsigned long", causing the
following warning when comparing with PAGE_SIZE, which is always "unsigned
long":

  fs/cifs/file.c: In function ‘cifs_readdata_to_iov’:
  fs/cifs/file.c:2757: warning: comparison of distinct pointer types lacks a cast

Introduced by commit 7f25bba8 ("cifs_iovec_read: keep iov_iter
between the calls of cifs_readdata_to_iov()"), which changed the
signedness of "remaining" and the code from min_t() to min().
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull slab changes from Pekka Enberg:
 "The biggest change is byte-sized freelist indices which reduces slab
  freelist memory usage:

    https://lkml.org/lkml/2013/12/2/64"

* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  mm: slab/slub: use page->list consistently instead of page->lru
  mm/slab.c: cleanup outdated comments and unify variables naming
  slab: fix wrongly used macro
  slub: fix high order page allocation problem with __GFP_NOFAIL
  slab: Make allocations with GFP_ZERO slightly more efficient
  slab: make more slab management structure off the slab
  slab: introduce byte sized index for the freelist of a slab
  slab: restrict the number of objects in a slab
  slab: introduce helper functions to get/set free object
  slab: factor out calculate nr objects in cache_estimate

Pull misc kbuild changes from Michal Marek:
 "Here is the non-critical part of kbuild:
   - One bogus coccinelle check removed, one check fixed not to suggest
     the obsolete PTR_RET macro
   - scripts/tags.sh does not index the generated *.mod.c files
   - new objdiff tool to list differences between two versions of an
     object file
   - A fix for scripts/bootgraph.pl"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  scripts/coccinelle: Use PTR_ERR_OR_ZERO
  scripts/bootgraph.pl: Add graphic header
  scripts: objdiff: detect object code changes between two commits
  Coccicheck: Remove memcpy to struct assignment test
  scripts/tags.sh: Ignore *.mod.c

This patch fixes I/O errors with the sym53c8xx_2 driver when the disk
returns QUEUE FULL status.

When the controller encounters an error (including QUEUE FULL or BUSY
status), it aborts all not yet submitted requests in the function
sym_dequeue_from_squeue.

This function aborts them with DID_SOFT_ERROR.

If the disk has full tag queue, the request that caused the overflow is
aborted with QUEUE FULL status (and the scsi midlayer properly retries
it until it is accepted by the disk), but the sym53c8xx_2 driver aborts
the following requests with DID_SOFT_ERROR --- for them, the midlayer
does just a few retries and then signals the error up to sd.

The result is that disk returning QUEUE FULL causes request failures.

The error was reproduced on 53c895 with COMPAQ BD03685A24 disk
(rebranded ST336607LC) with command queue 48 or 64 tags.  The disk has
64 tags, but under some access patterns it return QUEUE FULL when there
are less than 64 pending tags.  The SCSI specification allows returning
QUEUE FULL anytime and it is up to the host to retry.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 8f619b54 ("powerpc/ppc64: Do not turn AIL (reloc-on
interrupts) too early") added code to set the AIL bit in the LPCR
without checking whether the kernel is running in hypervisor mode.  The
result is that when the kernel is running as a guest (i.e., under
PowerKVM or PowerVM), the processor takes a privileged instruction
interrupt at that point, causing a panic.  The visible result is that
the kernel hangs after printing "returning from prom_init".

This fixes it by checking for hypervisor mode being available before
setting LPCR.  If we are not in hypervisor mode, we enable relocation-on
interrupts later in pSeries_setup_arch using the H_SET_MODE hcall.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commits 11d4616b ("futex: revert back to the explicit waiter
counting code") and 69cd9eba ("futex: avoid race between requeue and
wake") changed some of the finer details of how we think about futexes.
One was a late fix and the other a consequence of overlooking the whole
requeuing logic.

The first change caused our documentation to be incorrect, and the
second made us aware that we need to explicitly add more details to it.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull yet more networking updates from David Miller:

 1) Various fixes to the new Redpine Signals wireless driver, from
    Fariya Fatima.

 2) L2TP PPP connect code takes PMTU from the wrong socket, fix from
    Dmitry Petukhov.

 3) UFO and TSO packets differ in whether they include the protocol
    header in gso_size, account for that in skb_gso_transport_seglen().
   From Florian Westphal.

 4) If VLAN untagging fails, we double free the SKB in the bridging
    output path.  From Toshiaki Makita.

 5) Several call sites of sk->sk_data_ready() were referencing an SKB
    just added to the socket receive queue in order to calculate the
    second argument via skb->len.  This is dangerous because the moment
    the skb is added to the receive queue it can be consumed in another
    context and freed up.

    It turns out also that none of the sk->sk_data_ready()
    implementations even care about this second argument.

    So just kill it off and thus fix all these use-after-free bugs as a
    side effect.

 6) Fix inverted test in tcp_v6_send_response(), from Lorenzo Colitti.

 7) pktgen needs to do locking properly for LLTX devices, from Daniel
    Borkmann.

 8) xen-netfront driver initializes TX array entries in RX loop :-) From
    Vincenzo Maffione.

 9) After refactoring, some tunnel drivers allow a tunnel to be
    configured on top itself.  Fix from Nicolas Dichtel.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (46 commits)
  vti: don't allow to add the same tunnel twice
  gre: don't allow to add the same tunnel twice
  drivers: net: xen-netfront: fix array initialization bug
  pktgen: be friendly to LLTX devices
  r8152: check RTL8152_UNPLUG
  net: sun4i-emac: add promiscuous support
  net/apne: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  net: ipv6: Fix oif in TCP SYN+ACK route lookup.
  drivers: net: cpsw: enable interrupts after napi enable and clearing previous interrupts
  drivers: net: cpsw: discard all packets received when interface is down
  net: Fix use after free by removing length arg from sk_data_ready callbacks.
  Drivers: net: hyperv: Address UDP checksum issues
  Drivers: net: hyperv: Negotiate suitable ndis version for offload support
  Drivers: net: hyperv: Allocate memory for all possible per-pecket information
  bridge: Fix double free and memory leak around br_allowed_ingress
  bonding: Remove debug_fs files when module init fails
  i40evf: program RSS LUT correctly
  i40evf: remove open-coded skb_cow_head
  ixgb: remove open-coded skb_cow_head
  igbvf: remove open-coded skb_cow_head
  ...

Merge tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux

Pull blackfin updates from Steven Miao:
 "Code cleanup, some previously ignored patches, and bug fixes"

* tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux:
  blackfin: cleanup board files
  bf609: clock: drop unused clock bit set/clear functions
  Blackfin: bf537: rename "CONFIG_ADT75"
  Blackfin: bf537: rename "CONFIG_AD7314"
  Blackfin: bf537: rename ad2s120x ->ad2s1200
  blackfin: bf537: fix typo "CONFIG_SND_SOC_ADV80X_MODULE"
  blackfin: dma: current count mmr is read only
  bfin_crc: Move architecture independant crc header file out of the blackfin folder.
  bf54x: drop unuesd HOST status,control,timeout registers bit define macros
  blackfin: portmux: cleanup head file
  Blackfin: remove "config IP_CHECKSUM_L1"
  blackfin: Remove GENERIC_GPIO config option again
  blackfin:Use generic /proc/interrupts implementation
  blackfin: bf60x: fix typo "CONFIG_PM_BFIN_WAKE_PA15_POL"

Merge tag 'remoteproc-3.15-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc

Pull remoteproc cleanups from Ohad Ben-Cohen:
 "Several remoteproc cleanup patches coming from Jingoo Han, Julia
  Lawall and Uwe Kleine-König"

* tag 'remoteproc-3.15-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc:
  remoteproc/ste_modem: staticize local symbols
  remoteproc/davinci: simplify use of devm_ioremap_resource
  remoteproc/davinci: drop needless devm_clk_put

Pull llvm patches from Behan Webster:
 "These are some initial updates to support compiling the kernel with
  clang.

  These patches have been through the proper reviews to the best of my
  ability, and have been soaking in linux-next for a few weeks.  These
  patches by themselves still do not completely allow clang to be used
  with the kernel code, but lay the foundation for other patches which
  are still under review.

  Several other of the LLVMLinux patches have been already added via
  maintainer trees"

* tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel:
  x86: LLVMLinux: Fix "incomplete type const struct x86cpu_device_id"
  x86 kbuild: LLVMLinux: More cc-options added for clang
  x86, acpi: LLVMLinux: Remove nested functions from Thinkpad ACPI
  LLVMLinux: Add support for clang to compiler.h and new compiler-clang.h
  LLVMLinux: Remove warning about returning an uninitialized variable
  kbuild: LLVMLinux: Fix LINUX_COMPILER definition script for compilation with clang
  Documentation: LLVMLinux: Update Documentation/dontdiff
  kbuild: LLVMLinux: Adapt warnings for compilation with clang
  kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang