Currently, blk-mq uses a percpu_counter to keep track of how many
usages are in flight.  The percpu_counter is drained while freezing to
ensure that no usage is left in-flight after freezing is complete.
blk_mq_queue_enter/exit() and blk_mq_[un]freeze_queue() implement this
per-cpu gating mechanism.

This type of code has relatively high chance of subtle bugs which are
extremely difficult to trigger and it's way too hairy to be open coded
in blk-mq.  percpu_ref can serve the same purpose after the recent
changes.  This patch replaces the open-coded per-cpu usage counting
and draining mechanism with percpu_ref.

blk_mq_queue_enter() performs tryget_live on the ref and exit()
performs put.  blk_mq_freeze_queue() kills the ref and waits until the
reference count reaches zero.  blk_mq_unfreeze_queue() revives the ref
and wakes up the waiters.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Keeping __blk_mq_drain_queue() as a separate function doesn't buy us
anything and it's gonna be further simplified.  Let's flatten it into
its caller.

This patch doesn't make any functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

blk_mq freezing is entangled with generic bypassing which bypasses
blkcg and io scheduler and lets IO requests fall through the block
layer to the drivers in FIFO order.  This allows forward progress on
IOs with the advanced features disabled so that those features can be
configured or altered without worrying about stalling IO which may
lead to deadlock through memory allocation.

However, generic bypassing doesn't quite fit blk-mq.  blk-mq currently
doesn't make use of blkcg or ioscheds and it maps bypssing to
freezing, which blocks request processing and drains all the in-flight
ones.  This causes problems as bypassing assumes that request
processing is online.  blk-mq works around this by conditionally
allowing request processing for the problem case - during queue
initialization.

Another weirdity is that except for during queue cleanup, bypassing
started on the generic side prevents blk-mq from processing new
requests but doesn't drain the in-flight ones.  This shouldn't break
anything but again highlights that something isn't quite right here.

The root cause is conflating blk-mq freezing and generic bypassing
which are two different mechanisms.  The only intersecting purpose
that they serve is during queue cleanup.  Let's properly separate
blk-mq freezing from generic bypassing and simply use it where
necessary.

* request_queue->mq_freeze_depth is added and
  blk_mq_[un]freeze_queue() now operate on this counter instead of
  ->bypass_depth.  The replacement for QUEUE_FLAG_BYPASS isn't added
  but the counter is tested directly.  This will be further updated by
  later changes.

* blk_mq_drain_queue() is dropped and "__" prefix is dropped from
  blk_mq_freeze_queue().  Queue cleanup path now calls
  blk_mq_freeze_queue() directly.

* blk_queue_enter()'s fast path condition is simplified to simply
  check @q->mq_freeze_depth.  Previously, the condition was

	!blk_queue_dying(q) &&
	    (!blk_queue_bypass(q) || !blk_queue_init_done(q))

  mq_freeze_depth is incremented right after dying is set and
  blk_queue_init_done() exception isn't necessary as blk-mq doesn't
  start frozen, which only leaves the blk_queue_bypass() test which
  can be replaced by @q->mq_freeze_depth test.

This change simplifies the code and reduces confusion in the area.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue()
skip queue draining if bypass_depth was already above zero.  The
assumption is that the one which bumped the bypass_depth should have
performed draining already; however, there's nothing which prevents a
new instance of bypassing/freezing from starting before the previous
one finishes draining.  The current code may allow the later
bypassing/freezing instances to complete while there still are
in-flight requests which haven't finished draining.

Fix it by draining regardless of bypass_depth.  We still skip draining
from blk_queue_bypass_start() while the queue is initializing to avoid
introducing excessive delays during boot.  INIT_DONE setting is moved
above the initial blk_queue_bypass_end() so that bypassing attempts
can't slip inbetween.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

blk-mq uses a percpu_counter to keep track of how many usages are in
flight.  The percpu_counter is drained while freezing to ensure that
no usage is left in-flight after freezing is complete.

blk_mq_queue_enter/exit() and blk_mq_[un]freeze_queue() implement this
per-cpu gating mechanism; unfortunately, it contains a subtle bug -
smp_wmb() in blk_mq_queue_enter() doesn't prevent prevent the cpu from
fetching @q->bypass_depth before incrementing @q->mq_usage_counter and
if freezing happens inbetween the caller can slip through and freezing
can be complete while there are active users.

Use smp_mb() instead so that bypass_depth and mq_usage_counter
modifications and tests are properly interlocked.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu into for-3.17/core

Merge the percpu_ref changes from Tejun, he says they are stable now.

Pull ARM fixes from Russell King:
 "Another round of ARM fixes.  The largest change here is the L2 changes
  to work around problems for the Armada 37x/380 devices, where most of
  the size comes down to comments rather than code.

  The other significant fix here is for the ptrace code, to ensure that
  rewritten syscalls work as intended.  This was pointed out by Kees
  Cook, but Will Deacon reworked the patch to be more elegant.

  The remainder are fairly trivial changes"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8087/1: ptrace: reload syscall number after secure_computing() check
  ARM: 8086/1: Set memblock limit for nommu
  ARM: 8085/1: sa1100: collie: add top boot mtd partition
  ARM: 8084/1: sa1100: collie: revert back to cfi_probe
  ARM: 8080/1: mcpm.h: remove unused variable declaration
  ARM: 8076/1: mm: add support for HW coherent systems in PL310 cache

Note that I don't maintain Documentation/ABI/,
Documentation/devicetree/, or the language translation files.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

These days most people use git to send patches so I have added a section
about that.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On the syscall tracing path, we call out to secure_computing() to allow
seccomp to check the syscall number being attempted. As part of this, a
SIGTRAP may be sent to the tracer and the syscall could be re-written by
a subsequent SET_SYSCALL ptrace request. Unfortunately, this new syscall
is ignored by the current code unless TIF_SYSCALL_TRACE is also set on
the current thread.

This patch slightly reworks the enter path of the syscall tracing code
so that we always reload the syscall number from
current_thread_info()->syscall after the potential ptrace traps.
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Commit 1c2f87c2 (ARM: 8025/1: Get rid of meminfo) changed find_limits
to use memblock_get_current_limit for calculating the max_low pfn.
nommu targets never actually set a limit on memblock though which
means memblock_get_current_limit will just return the default
value. Set the memblock_limit to be the end of DDR to make sure
bounds are calculated correctly.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The CFI mapping is now perfect so we can expose the top block, read only.
There isn't much to read, though, just the sharpsl_params values.
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Reverts commit d26b17ed
ARM: sa1100: collie.c: fall back to jedec_probe flash detection

Unfortunately the detection was challenged on the defective unit used for tests:
one of the NOR chips did not respond to the CFI query.
Moreover that bad device needed extra delays on erase-suspend/resume cycles.

Tested personally on 3 different units and with feedback of two other users.
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The sync_phys variable has been replaced by link time computation in
mcpm_head.S before the code was submitted upstream.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

When a PL310 cache is used on a system that provides hardware
coherency, the outer cache sync operation is useless, and can be
skipped. Moreover, on some systems, it is harmful as it causes
deadlocks between the Marvell coherency mechanism, the Marvell PCIe
controller and the Cortex-A9.

To avoid this, this commit introduces a new Device Tree property
'arm,io-coherent' for the L2 cache controller node, valid only for the
PL310 cache. It identifies the usage of the PL310 cache in an I/O
coherent configuration. Internally, it makes the driver disable the
outer cache sync operation.

Note that technically speaking, a fully coherent system wouldn't
require any of the other .outer_cache operations. However, in
practice, when booting secondary CPUs, these are not yet coherent, and
therefore a set of cache maintenance operations are necessary at this
point. This explains why we keep the other .outer_cache operations and
only ->sync is disabled.

While in theory any write to a PL310 register could cause the
deadlock, in practice, disabling ->sync is sufficient to workaround
the deadlock, since the other cache maintenance operations are only
used in very specific situations.

Contrary to previous versions of this patch, this new version does not
simply NULL-ify the ->sync member, because the l2c_init_data
structures are now 'const' and therefore cannot be modified, which is
a good thing. Therefore, this patch introduces a separate
l2c_init_data instance, called of_l2c310_coherent_data.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull spi fixes from Mark Brown:
 "A few driver specific fixes, the biggest one being a fix for the newly
  added Qualcomm SPI controller driver to make it not use its internal
  chip select due to hardware bugs, replacing it with GPIOs"

* tag 'spi-v3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: qup: Remove chip select function
  spi: qup: Fix order of spi_register_master
  spi: sh-sci: fix use-after-free in sh_sci_spi_remove()
  spi/pxa2xx: fix incorrect SW mode chipselect setting for BayTrail LPSS SPI

Pull regulator fixes from Mark Brown:
 "Several driver specific fixes here, the palmas fixes being especially
  important for a range of boards - the recent updates to support new
  devices have introduced several regressions"

* tag 'regulator-v3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: tps65218: Correct the the config register for LDO1
  regulator: tps65218: Add the missing of_node assignment in probe
  regulator: palmas: fix typo in enable_reg calculation
  regulator: bcm590xx: fix vbus name
  regulator: palmas: Fix SMPS enable/disable/is_enabled

Pull SCSI target fixes from Nicholas Bellinger:
 "Mostly minor fixes this time around.  The highlights include:

   - iscsi-target CHAP authentication fixes to enforce explicit key
     values (Tejas Vaykole + rahul.rane)
   - fix a long-standing OOPs in target-core when a alua configfs
     attribute is accessed after port symlink has been removed.
     (Sebastian Herbszt)
   - fix a v3.10.y iscsi-target regression causing the login reject
     status class/detail to be ignored (Christoph Vu-Brugier)
   - fix a v3.10.y iscsi-target regression to avoid rejecting an
     existing ITT during Data-Out when data-direction is wrong (Santosh
     Kulkarni + Arshad Hussain)
   - fix a iscsi-target related shutdown deadlock on UP kernels (Mikulas
     Patocka)
   - fix a v3.16-rc1 build issue with vhost-scsi + !CONFIG_NET (MST)"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iscsi-target: fix iscsit_del_np deadlock on unload
  iovec: move memcpy_from/toiovecend to lib/iovec.c
  iscsi-target: Avoid rejecting incorrect ITT for Data-Out
  tcm_loop: Fix memory leak in tcm_loop_submission_work error path
  iscsi-target: Explicily clear login response PDU in exception path
  target: Fix left-over se_lun->lun_sep pointer OOPs
  iscsi-target; Enforce 1024 byte maximum for CHAP_C key value
  iscsi-target: Convert chap_server_compute_md5 to use kstrtoul

Merge remote-tracking branches 'regulator/fix/bcm590xx', 'regulator/fix/palmas' and 'regulator/fix/tps65218' into regulator-linus

Now that explicit invocation of percpu_ref_exit() is necessary to free
the percpu counter, we can implement percpu_ref_reinit() which
reinitializes a released percpu_ref.  This can be used implement
scalable gating switch which can be drained and then re-opened without
worrying about memory allocation failures.

percpu_ref_is_zero() is added to be used in a sanity check in
percpu_ref_exit().  As this function will be useful for other purposes
too, make it a public interface.

v2: Use smp_read_barrier_depends() instead of smp_load_acquire().  We
    only need data dep barrier and smp_load_acquire() is stronger and
    heavier on some archs.  Spotted by Lai Jiangshan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>

Currently, a percpu_ref undoes percpu_ref_init() automatically by
freeing the allocated percpu area when the percpu_ref is killed.
While seemingly convenient, this has the following niggles.

* It's impossible to re-init a released reference counter without
  going through re-allocation.

* In the similar vein, it's impossible to initialize a percpu_ref
  count with static percpu variables.

* We need and have an explicit destructor anyway for failure paths -
  percpu_ref_cancel_init().

This patch removes the automatic percpu counter freeing in
percpu_ref_kill_rcu() and repurposes percpu_ref_cancel_init() into a
generic destructor now named percpu_ref_exit().  percpu_ref_destroy()
is considered but it gets confusing with percpu_ref_kill() while
"exit" clearly indicates that it's the counterpart of
percpu_ref_init().

All percpu_ref_cancel_init() users are updated to invoke
percpu_ref_exit() instead and explicit percpu_ref_exit() calls are
added to the destruction path of all percpu_ref users.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Li Zefan <lizefan@huawei.com>

percpu_ref->pcpu_count is a percpu pointer with a status flag in its
lowest bit.  As such, it always goes through arithmetic operations
which is very cumbersome to do on a pointer.  It has to be first
casted to unsigned long and then back.

Let's just make the field unsigned long so that we can skip the first
casts.  While at it, rename it to pcpu_counter_ptr to clarify that
it's a pointer value.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>

* All four percpu_ref_*() operations implemented in the header file
  perform the same operation to determine whether the percpu_ref is
  alive and extract the percpu pointer.  Factor out the common logic
  into __pcpu_ref_alive().  This doesn't change the generated code.

* There are a couple places in percpu-refcount.c which masks out
  PCPU_REF_DEAD to obtain the percpu pointer.  Factor it out into
  pcpu_count_ptr().

* The above changes make the WARN_ON_ONCE() conditional at the top of
  percpu_ref_kill_and_confirm() the only user of REF_STATUS().  Test
  PCPU_REF_DEAD directly and remove REF_STATUS().

This patch doesn't introduce any functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>

percpu-refcount currently reserves two lowest bits of its percpu
pointer to indicate its state; however, only one bit is used for
PCPU_REF_DEAD.

Simplify it by removing PCPU_STATUS_BITS/MASK and testing
PCPU_REF_DEAD directly.  This also allows the compiler to choose a
more efficient instruction depending on the architecture.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>

ioctx_alloc() reaches inside percpu_ref and directly frees
->pcpu_count in its failure path, which is quite gross.  percpu_ref
has been providing a proper interface to do this,
percpu_ref_cancel_init(), for quite some time now.  Let's use that
instead.

This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Kent Overstreet <kmo@daterainc.com>

On uniprocessor preemptible kernel, target core deadlocks on unload. The
following events happen:
* iscsit_del_np is called
* it calls send_sig(SIGINT, np->np_thread, 1);
* the scheduler switches to the np_thread
* the np_thread is woken up, it sees that kthread_should_stop() returns
  false, so it doesn't terminate
* the np_thread clears signals with flush_signals(current); and goes back
  to sleep in iscsit_accept_np
* the scheduler switches back to iscsit_del_np
* iscsit_del_np calls kthread_stop(np->np_thread);
* the np_thread is waiting in iscsit_accept_np and it doesn't respond to
  kthread_stop

The deadlock could be resolved if the administrator sends SIGINT signal to
the np_thread with killall -INT iscsi_np

The reproducible deadlock was introduced in commit
db6077fd, but the thread-stopping code was
racy even before.

This patch fixes the problem. Using kthread_should_stop to stop the
np_thread is unreliable, so we test np_thread_state instead. If
np_thread_state equals ISCSI_NP_THREAD_SHUTDOWN, the thread exits.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Pull IOMMU fixes from Joerg Roedel:

 - fix VT-d regression with handling multiple RMRR entries per device

 - fix a small race that was left in the mmu_notifier handling in the
   AMD IOMMUv2 driver

* tag 'iommu-fixes-v3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Fix small race between invalidate_range_end/start
  iommu/vt-d: fix bug in handling multiple RMRRs for the same PCI device

Pull x86 fixes from Peter Anvin:
 "A pile of fixes related to the VDSO, EFI and 32-bit badsys handling.

  It turns out that removing the section headers from the VDSO breaks
  gdb, so this puts back most of them.  A very simple typo broke
  rt_sigreturn on some versions of glibc, with obviously disastrous
  results.  The rest is pretty much fixes for the corresponding fallout.

  The EFI fixes fixes an arithmetic overflow on 32-bit systems and
  quiets some build warnings.

  Finally, when invoking an invalid system call number on x86-32, we
  bypass a bunch of handling, which can make the audit code oops"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi-pstore: Fix an overflow on 32-bit builds
  x86/vdso: Error out in vdso2c if DT_RELA is present
  x86/vdso: Move DISABLE_BRANCH_PROFILING into the vdso makefile
  x86_32, signal: Fix vdso rt_sigreturn
  x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508)
  x86/vdso: Create .build-id links for unstripped vdso files
  x86/vdso: Remove some redundant in-memory section headers
  x86/vdso: Improve the fake section headers
  x86/vdso2c: Use better macros for ELF bitness
  x86/vdso: Discard the __bug_table section
  efi: Fix compiler warnings (unused, const, type)

Pull MIPS fixes from Ralf Baechle:
 "This is dominated by a large number of changes necessary for the MIPS
  BPF code.  code.  Aside of that there are

   - a fix for the MSC system controller support code.
   - a Turbochannel fix.
   - a recordmcount fix that's MIPS-specific.
   - barrier fixes to smp-cps / pm-cps after unrelated changes elsewhere
     in the kernel.
   - revert support for MSA registers in the signal frames.  The
     reverted patch did modify the signal stack frame which of course is
     inacceptable.
   - fix math-emu build breakage with older compilers.
   - some related cleanup.
   - fix Lasat build error if CONFIG_CRC32 isn't set to y by the user"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (27 commits)
  MIPS: Lasat: Fix build error if CRC32 is not enabled.
  TC: Handle device_register() errors.
  MIPS: MSC: Prevent out-of-bounds writes to MIPS SC ioremap'd region
  MIPS: bpf: Fix stack space allocation for BPF memwords on MIPS64
  MIPS: BPF: Use 32 or 64-bit load instruction to load an address to register
  MIPS: bpf: Fix PKT_TYPE case for big-endian cores
  MIPS: BPF: Prevent kernel fall over for >=32bit shifts
  MIPS: bpf: Drop update_on_xread and always initialize the X register
  MIPS: bpf: Fix is_range() semantics
  MIPS: bpf: Use pr_debug instead of pr_warn for unhandled opcodes
  MIPS: bpf: Fix return values for VLAN_TAG_PRESENT case
  MIPS: bpf: Use correct mask for VLAN_TAG case
  MIPS: bpf: Fix branch conditional for BPF_J{GT/GE} cases
  MIPS: bpf: Add SEEN_SKB to flags when looking for the PKT_TYPE
  MIPS: bpf: Use 'andi' instead of 'and' for the VLAN cases
  MIPS: bpf: Return error code if the offset is a negative number
  MIPS: bpf: Use the LO register to get division's quotient
  MIPS: mm: uasm: Fix lh micro-assembler instruction
  MIPS: uasm: Add SLT uasm instruction
  MIPS: uasm: Add s3s1s2 instruction builder
  ...

Pull ARC fixes from Vineet Gupta:
 "Some SMP changes, a ptrace request for NPTL debugging, bunch of build
  breakages/warnings"

* tag 'arc-fixes-for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [SMP] Enable icache coherency
  ARC: [SMP] Fix IPI IRQ registration
  ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)
  ARC: optimize kernel bss clearing in early boot code
  ARC: Fix build breakage for !CONFIG_ARC_DW2_UNWIND
  ARC: fix build warning in devtree
  ARC: remove checks for CONFIG_ARC_MMU_V4

Pull compress bugfix from Greg KH:
 "Here is another lz4 bugfix for 3.16-rc3 that resolves a reported issue
  with that compression algorithm"

* tag 'compress-3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  lz4: fix another possible overrun

Merge tag 'stable/for-linus-3.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

Pull swiotlb bugfix from Konrad Rzeszutek Wilk:
 "One bug-fix that had been in tree for quite some time.  We had assumed
  that the physical address zero was invalid and would fail it.  But
  that is not true and on some architectures it is not reserved and
  valid.  This fixes it"

* tag 'stable/for-linus-3.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: don't assume PA 0 is invalid

Pull sound fixes from Takashi Iwai:
 "Here includes a few patchset for fixing mostly HD-audio issues in
  addition to a patch assuring the compress API bytes alignment and a
  fix for the die-hard existing race condition at USB-audio
  disconnection.  The volume looks big in Realtek HD-audio code, but
  it's just a translation of the fixup tables, and the actual changes
  are rather trivial"

* tag 'sound-3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - restore BCLK M/N values when resuming HSW/BDW display controller
  ALSA: usb-audio: Fix races at disconnection and PCM closing
  ALSA: hda - Adjust speaker HPF and add LED support for HP Spectre 13
  ALSA: hda - Make the pin quirk tables use the SND_HDA_PIN_QUIRK macro
  ALSA: hda - Make a SND_HDA_PIN_QUIRK macro
  ALSA: hda - Add pin quirk for Dell XPS 15
  ALSA: hda - hdmi: call overridden init on resume
  ALSA: hda - Fix usage of "model" module parameter
  ALSA: compress: fix the struct alignment to 4 bytes

Pull MFD fixes from Lee Jones:
 "Couple of simple fixes due for the v3.16 -rcs"

* tag 'mfd-fixes-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
  mfd: ab8500: Fix dt irq mapping
  mfd: davinci: Voicecodec needs regmap_mmio
  mfd: STw481x: Allow modular build
  mfd: UCB1x00: Enable modular build

Pull drm fixes from Dave Airlie:
 "Exynos, i915 and msm fixes and one core fix.

  exynos:
     hdmi power off and mixer issues

  msm:
     iommu, build fixes,

  i915:
     regression races and warning fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (22 commits)
  drm/i915: vlv_prepare_pll is only needed in case of non DSI interfaces
  drm: fix NULL pointer access by wrong ioctl
  drm/exynos: enable vsync interrupt while waiting for vblank
  drm/exynos: soft reset mixer before reconfigure after power-on
  drm/exynos: allow multiple layer updates per vsync for mixer
  drm/i915: Hold the table lock whilst walking the file's idr and counting the objects in debugfs
  drm/i915: BDW: Adding Reserved PCI IDs.
  drm/i915: Only mark the ctx as initialised after a SET_CONTEXT operation
  drm/exynos: stop mixer before gating clocks during poweroff
  drm/exynos: set power state variable after enabling clocks and power
  drm/exynos: disable unused windows on apply
  drm/exynos: Fix de-registration ordering
  drm/exynos: change zero to NULL for sparse
  drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings
  drm/exynos: hdmi: fix power order issue
  drm/i915: default to having backlight if VBT not available
  drm/i915: cache hw power well enabled state
  drm/msm: fix IOMMU cleanup for -EPROBE_DEFER
  drm/msm: use PAGE_ALIGNED instead of IS_ALIGNED(PAGE_SIZE)
  drm/msm/hdmi: set hdp clock rate before prepare_enable
  ...

ERROR: "memcpy_fromiovecend" [drivers/vhost/vhost_scsi.ko] undefined!

commit 9f977ef7
    vhost-scsi: Include prot_bytes into expected data transfer length
in target-pending makes drivers/vhost/scsi.c call memcpy_fromiovecend().
This function is not available when CONFIG_NET is not enabled.

socket.h already includes uio.h, so no callers need updating.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch changes iscsit_check_dataout_hdr() to dump the incoming
Data-Out payload when the received ITT is not associated with a
WRITE, instead of calling iscsit_reject_cmd() for the non WRITE
ITT descriptor.

This addresses a bug where an initiator sending an Data-Out for
an ITT associated with a READ would end up generating a reject
for the READ, eventually resulting in list corruption.
Reported-by: Santosh Kulkarni <santosh.kulkarni@calsoftinc.com>
Reported-by: Arshad Hussain <arshad.hussain@calsoftinc.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

There is one other possible overrun in the lz4 code as implemented by
Linux at this point in time (which differs from the upstream lz4
codebase, but will get synced at in a future kernel release.)  As
pointed out by Don, we also need to check the overflow in the data
itself.

While we are at it, replace the odd error return value with just a
"simple" -1 value as the return value is never used for anything other
than a basic "did this work or not" check.
Reported-by: "Don A. Bailey" <donb@securitymouse.com>
Reported-by: Willy Tarreau <w@1wt.eu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>