Currently, a reader will check first to make sure that the writer mode
byte is cleared before incrementing the reader count. That waiting is
not really necessary. It increases the latency in the reader/writer
to reader transition and reduces readers performance.

This patch eliminates that waiting. It also has the side effect
of reducing the chance of writer lock stealing and improving the
fairness of the lock. Using a locking microbenchmark, a 10-threads 5M
locking loop of mostly readers (RW ratio = 10,000:1) has the following
performance numbers in a Haswell-EX box:

        Kernel          Locking Rate (Kops/s)
        ------          ---------------------
        4.1.1               15,063,081
        4.1.1+patch         17,241,552  (+14.4%)
Signed-off-by: NWaiman Long <Waiman.Long@hp.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1436459543-29126-2-git-send-email-Waiman.Long@hp.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When we unlock in __pv_queued_spin_unlock(), a failed cmpxchg() on the lock
value indicates that we need to take the slow-path and unhash the
corresponding node blocked on the lock.

Since a failed cmpxchg() does not provide any memory-ordering guarantees,
it is possible that the node data could be read before the cmpxchg() on
weakly-ordered architectures and therefore return a stale value, leading
to hash corruption and/or a BUG().

This patch adds an smb_rmb() following the failed cmpxchg operation, so
that the unhashing is ordered after the lock has been checked.
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
[ Added more comments]
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NWaiman Long <Waiman.Long@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steve Capper <Steve.Capper@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150713155830.GL2632@arm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

A failed cmpxchg does not provide any memory ordering guarantees, a
property that is used to optimise the cmpxchg implementations on Alpha,
PowerPC and arm64.

This patch updates atomic_ops.txt and memory-barriers.txt to reflect
this.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hp.com>
Link: http://lkml.kernel.org/r/20150716151006.GH26390@arm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

 - Rename the on-stack variable to match the datastructure variable,

 - place the cmpxchg back under the comment that explains it,

 - clean up the WARN() statement to avoid superfluous conditionals
   and line-breaks.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Merge branch 'locking/urgent', tag 'v4.2-rc5' into locking/core, to pick up fixes before applying new changes
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pull powerpc fixes from Michael Ellerman:
 - TCE table memory calculation fix from Alexey
 - Build fix for ans-lcd from Luis
 - Unbalanced IRQ warning fix from Alistair

* tag 'powerpc-4.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/eeh-powernv: Fix unbalanced IRQ warning
  macintosh/ans-lcd: fix build failure after module_init/exit relocation
  powerpc/powernv/ioda2: Fix calculation for memory allocated for TCE table

Ted Ts'o reports that his Lenovo T540p ThinkPad crashes at boot if
attached to the docking station.  This is a regression that he was able
to bisect to commit 8c7b5ccb: "drm/i915: Use atomic helpers for
computing changed flags:"

The reason seems to be the new call to drm_atomic_helper_check_modeset()
added to intel_modeset_compute_config(), which in turn calls
update_connector_routing(), and somehow ends up picking a NULL crtc for
the connector state, causing the subsequent drm_crtc_index() to OOPS.

Daniel Vetter says that the fundamental issue seems to be confusion in
the encoder selection, and this isn't the right fix, but while he chases
down the proper fix, this at least avoids the NULL pointer dereference
and makes Ted's docking station work again.
Reported-bisected-and-tested-by: NTheodore Ts'o <tytso@mit.edu>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Mani Nikula <jani.nikula@linux.intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull SCSI fixes from James Bottomley:
 "A set of three fixes for the ipr driver and one fairly major one for
  memory leaks in the mq path of SCSI"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: fix memory leak with scsi-mq
  ipr: Fix invalid array indexing for HRRQ
  ipr: Fix incorrect trace indexing
  ipr: Fix locking for unit attention handling

Pull ARM SoC fixes from Olof Johansson:
 "Things are calming down nicely here w.r.t. fixes.  This batch
  includes two week's worth since I missed to send before -rc4.

  Nothing particularly scary to point out, smaller fixes here and there.
  Shortlog describes it pretty well"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: keystone: fix dt bindings to use post div register for mainpll
  ARM: nomadik: disable UART0 on Nomadik boards
  ARM: dts: i.MX35: Fix can support.
  ARM: OMAP2+: hwmod: Fix _wait_target_ready() for hwmods without sysc
  ARM: dts: add CPU OPP and regulator supply property for exynos4210
  ARM: dts: Update video-phy node with syscon phandle for exynos3250
  ARM: DRA7: hwmod: fix gpmc hwmod

Pull VFS fix from Al Viro:
 "Spurious ENOTDIR fix"

This should fix the problems reported by Dominique Martinet and Hugh
Dickins.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  link_path_walk(): be careful when failing with ENOTDIR

In RCU mode we might end up with dentry evicted just we check
that it's a directory.  In such case we should return ECHILD
rather than ENOTDIR, so that pathwalk would be retries in non-RCU
mode.

Breakage had been introduced in commit b18825a7 - prior to that
we were looking at nd->inode, which had been fetched before
verifying that ->d_seq was still valid.  That form of check
would only be satisfied if at some point the pathname prefix
would indeed have resolved to a non-directory.  The fix consists
of checking ->d_seq after we'd run into a non-directory dentry,
and failing with ECHILD in case of mismatch.

Note that all branches since 3.12 have that problem...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull dmaengine fixes from Vinod Koul:
 "We had a regression due to reuse of descriptor so we have reverted
  that.

  The rest are driver fixes:

   - at_hdmac and at_xdmac for residue, trannfer width, and channel config
   - pl330 final fix for dma fails and overflow issue
   - xgene resouce map fix
   - mv_xor big endian op fix"

* tag 'dmaengine-fix-4.2-rc5' of git://git.infradead.org/users/vkoul/slave-dma:
  Revert "dmaengine: virt-dma: don't always free descriptor upon completion"
  dmaengine: mv_xor: fix big endian operation in register mode
  dmaengine: xgene-dma: Fix the resource map to handle overlapping
  dmaengine: at_xdmac: fix transfer data width in at_xdmac_prep_slave_sg()
  dmaengine: at_hdmac: fix residue computation
  dmaengine: at_xdmac: fix bug about channel configuration
  dmaengine: pl330: Really fix choppy sound because of wrong residue calculation
  dmaengine: pl330: Fix overflow when reporting residue in memcpy

Pull irq fixlets from Thomas Gleixner:
 "Just two updates to the maintainers file"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Appoint Jiang and Marc as irqdomain maintainers
  MAINTAINERS: Appoint Marc Zyngier as irqchips co-maintainer

Pull x86 fixes from Ingo Molnar:
 "Fallout from the recent NMI fixes: make x86 LDT handling more robust.

  Also some EFI fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ldt: Make modify_ldt synchronous
  x86/xen: Probe target addresses in set_aliased_prot() before the hypercall
  x86/irq: Use the caller provided polarity setting in mp_check_pin_attr()
  efi: Check for NULL efi kernel parameters
  x86/efi: Use all 64 bit of efi_memmap in setup_e820()

Pull networking fixes from David Miller:

 1) Must teardown SR-IOV before unregistering netdev in igb driver, from
    Alex Williamson.

 2) Fix ipv6 route unreachable crash in IPVS, from Alex Gartrell.

 3) Default route selection in ipv4 should take the prefix length, table
    ID, and TOS into account, from Julian Anastasov.

 4) sch_plug must have a reset method in order to purge all buffered
    packets when the qdisc is reset, likewise for sch_choke, from WANG
    Cong.

 5) Fix deadlock and races in slave_changelink/br_setport in bridging.
    From Nikolay Aleksandrov.

 6) mlx4 bug fixes (wrong index in port even propagation to VFs,
    overzealous BUG_ON assertion, etc.) from Ido Shamay, Jack
    Morgenstein, and Or Gerlitz.

 7) Turn off klog message about SCTP userspace interface compat that
    makes no sense at all, from Daniel Borkmann.

 8) Fix unbounded restarts of inet frag eviction process, causing NMI
    watchdog soft lockup messages, from Florian Westphal.

 9) Suspend/resume fixes for r8152 from Hayes Wang.

10) Fix busy loop when MSG_WAITALL|MSG_PEEK is used in TCP recv, from
    Sabrina Dubroca.

11) Fix performance regression when removing a lot of routes from the
    ipv4 routing tables, from Alexander Duyck.

12) Fix device leak in AF_PACKET, from Lars Westerhoff.

13) AF_PACKET also has a header length comparison bug due to signedness,
    from Alexander Drozdov.

14) Fix bug in EBPF tail call generation on x86, from Daniel Borkmann.

15) Memory leaks, TSO stats, watchdog timeout and other fixes to
    thunderx driver from Sunil Goutham and Thanneeru Srinivasulu.

16) act_bpf can leak memory when replacing programs, from Daniel
    Borkmann.

17) WOL packet fixes in gianfar driver, from Claudiu Manoil.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (79 commits)
  stmmac: fix missing MODULE_LICENSE in stmmac_platform
  gianfar: Enable device wakeup when appropriate
  gianfar: Fix suspend/resume for wol magic packet
  gianfar: Fix warning when CONFIG_PM off
  act_pedit: check binding before calling tcf_hash_release()
  net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket
  net: sched: fix refcount imbalance in actions
  r8152: reset device when tx timeout
  r8152: add pre_reset and post_reset
  qlcnic: Fix corruption while copying
  act_bpf: fix memory leaks when replacing bpf programs
  net: thunderx: Fix for crash while BGX teardown
  net: thunderx: Add PCI driver shutdown routine
  net: thunderx: Fix crash when changing rss with mutliple traffic flows
  net: thunderx: Set watchdog timeout value
  net: thunderx: Wakeup TXQ only if CQE_TX are processed
  net: thunderx: Suppress alloc_pages() failure warnings
  net: thunderx: Fix TSO packet statistic
  net: thunderx: Fix memory leak when changing queue count
  net: thunderx: Fix RQ_DROP miscalculation
  ...

Pull btrfs fixes from Chris Mason:
 "Filipe fixed up a hard to trigger ENOSPC regression from our merge
  window pull, and we have a few other smaller fixes"

* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix quick exhaustion of the system array in the superblock
  btrfs: its btrfs_err() instead of btrfs_error()
  btrfs: Avoid NULL pointer dereference of free_extent_buffer when read_tree_block() fail
  btrfs: Fix lockdep warning of btrfs_run_delayed_iputs()

Pull sound fixes from Takashi Iwai:
 "This became a relative big update as it includes the collected ASoC
  fixes.  There are a few fixes in ASoC core side, mostly for DAPM and
  the new topology API.  The rest are various ASoC driver-specific
  fixes, as well as the usual HD-audio and USB-audio quirks"

* tag 'sound-4.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (29 commits)
  ALSA: hda - Fix MacBook Pro 5,2 quirk
  ALSA: hda - Fix race between PM ops and HDA init/probe
  ALSA: usb-audio: add dB range mapping for some devices
  ALSA: hda - Apply a fixup to Dell Vostro 5480
  ALSA: hda - Add pin quirk for the headset mic jack detection on Dell laptop
  ALSA: hda - Apply fixup for another Toshiba Satellite S50D
  ALSA: fireworks: add support for AudioFire2 quirk
  ALSA: hda - Fix the headset mic that will not work on Dell desktop machine
  ALSA: hda - fix cs4210_spdif_automute()
  ASoC: pcm1681: Fix setting de-emphasis sampling rate selection
  ASoC: ssm4567: Keep TDM_BCLKS in ssm4567_set_dai_fmt
  ASoC: sgtl5000: Fix up define for SGTL5000_SMALL_POP
  ASoC: dapm: Don't add prefix to widget stream name
  ASoC: rt5645: Check if codec is initialized in workqueue handler
  ASoC: Intel: Get correct usage_count value to load firmware
  ASoC: topology: Fix to add dapm mixer info
  ASoC: zx: spdif: Fix devm_ioremap_resource return value check
  ASoC: zx: i2s: Fix devm_ioremap_resource return value check
  ASoC: mediatek: Use platform_of_node for machine drivers
  ASoC: Free card DAPM context on snd_soc_instantiate_card() error path
  ...

Commit 50649ab1 ("stmmac: drop driver from stmmac platform code")
was a bit overzealous in removing code and dropped the MODULE_*
macro's that are still needed since stmmac_platform can be a module.
Fix this by putting the macro's remvoed in 50649ab1 back.

This fixes the following errors when used as a module:
  stmmac_platform: module license 'unspecified' taints kernel.
  Disabling lock debugging due to kernel taint
  stmmac_platform: Unknown symbol devm_kmalloc (err 0)
  stmmac_platform: Unknown symbol stmmac_suspend (err 0)
  stmmac_platform: Unknown symbol platform_get_irq_byname (err 0)
  stmmac_platform: Unknown symbol stmmac_dvr_remove (err 0)
  stmmac_platform: Unknown symbol platform_get_resource (err 0)
  stmmac_platform: Unknown symbol of_get_phy_mode (err 0)
  stmmac_platform: Unknown symbol of_property_read_u32_array (err 0)
  stmmac_platform: Unknown symbol of_alias_get_id (err 0)
  stmmac_platform: Unknown symbol stmmac_resume (err 0)
  stmmac_platform: Unknown symbol stmmac_dvr_probe (err 0)

Fixes: 50649ab1 ("stmmac: drop driver from stmmac platform code")
Reported-by: NIgor Gnatenko <i.gnatenko.brain@gmail.com>
Signed-off-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Claudiu Manoil says:

====================
gianfar: wol magic packet fixes

These changes were already validated as part of FSL SDK.
Patch 2 fixes occasional wake-on magic packet failures during
traffic, probably due to incorrect traffic stop/ device halt
sequence and incorrect usage of txlock.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The wol_en flag is 0 by default anyway, and we have the
following inconsistency: a MAGIC packet wol capable eth
interface is registered as a wake-up source but unable
to wake-up the system as wol_en is 0 (wake-on flag set to 'd').
Calling set_wakeup_enable() at netdev open is just redundant
because wol_en is 0 by default.
Let only ethtool call set_wakeup_enable() for now.

The bflock is obviously obsoleted, its utility has been corroded
over time.  The bitfield flags used today in gianfar are accessed
only on the init/ config path, with no real possibility of
concurrency - nothing that would justify smth. like bflock.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we disable NAPI in the first place we can mask the device's
interrupts (and halt it) without fearing that imask may be
concurrently accessed from interrupt context, so there's
no need to do local_irq_save() around gfar_halt_nodisable().
lock_rx_qs()/unlock_tx_qs() are just obsoleted and potentially
buggy routines.  The txlock is currently used in the driver only
to manage TX congestion, it has nothing to do with halting the
device.  With these changes, the TX processing is stopped before
gfar_halt().

Compact gfar_halt() is used instead of gfar_halt_nodisable(),
as it disables Rx/TX DMA h/w blocks and the Rx/TX h/w queues.
gfar_start() re-enables all these blocks on resume.  Enabling
the magic-packet mode remains the same, note that the RX block
is re-enabled just before entering sleep mode.

Add IRQF_NO_SUSPEND flag for the error interrupt line, to signal
that the interrupt line must remain active during sleep in order
to wake the system by magic packet (MAG) reception interrupt.
(On some systems the MAG interrupt did trigger w/o this flag
as well, but on others it didn't.)

Without these fixes, when suspended during fair Tx traffic the
interface occasionally failed to be woken up by magic packet.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CC      drivers/net/ethernet/freescale/gianfar.o
drivers/net/ethernet/freescale/gianfar.c:568:13: warning: 'lock_tx_qs'
defined but not used [-Wunused-function]
 static void lock_tx_qs(struct gfar_private *priv)
             ^
drivers/net/ethernet/freescale/gianfar.c:576:13: warning: 'unlock_tx_qs'
defined but not used [-Wunused-function]
 static void unlock_tx_qs(struct gfar_private *priv)
             ^
Reported-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we share an action within a filter, the bind refcnt
should increase, therefore we should not call tcf_hash_release().

Fixes: 1a29321e ("net_sched: act: Dont increment refcnt on replace")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NCong Wang <cwang@twopensource.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All of the keystone devices have a separate register to hold post
divider value for main pll clock. Currently the fixed-postdiv
value used for k2hk/l/e SoCs works by sheer luck as u-boot happens to
use a value of 2 for this. Now that we have fixed this in the pll
clock driver change the dt bindings for the same.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Pull IOMMU fixes from Joerg Roedel:
 "These fixes are all for the AMD IOMMU driver:

   - A regression with HSA caused by the conversion of the driver to
     default domains.  The fixes make sure that an HSA device can still
     be attached to an IOMMUv2 domain and that these domains also allow
     non-IOMMUv2 capable devices.

   - Fix iommu=pt mode which did not work because the dma_ops where set
     to nommu_ops, which breaks devices that can only do 32bit DMA.

   - Fix an issue with non-PCI devices not working, because there are no
     dma_ops for them.  This issue was discovered recently as new AMD
     x86 platforms have non-PCI devices too"

* tag 'iommu-fixes-v4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Allow non-ATS devices in IOMMUv2 domains
  iommu/amd: Set global dma_ops if swiotlb is disabled
  iommu/amd: Use swiotlb in passthrough mode
  iommu/amd: Allow non-IOMMUv2 devices in IOMMUv2 domains
  iommu/amd: Use iommu core for passthrough mode
  iommu/amd: Use iommu_attach_group()

Pull drm intel fixes from Daniel Vetter:
 "I delayed my -fixes pull a bit hoping that I could include a fix for
  the dp mst stuff but looks a bit more nasty than that.  So just 3
  other regression fixes, one 4.2 other two cc: stable"

* tag 'drm-intel-fixes-2015-07-31' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Declare the swizzling unknown for L-shaped configurations
  drm/i915: Mark PIN_USER binding as GLOBAL_BIND without the aliasing ppgtt
  drm/i915: Replace WARN inside I915_READ64_2x32 with retry loop

Pull drm fixes from Dave Airlie:
 "This has a bunch of nouveau fixes, as Ben has been hibernating and has
  lots of small fixes for lots of bugs across nouveau.

  Radeon has one major fix for hdmi/dp audio regression that is larger
  than Alex would like, but seems to fix up a fair few bugs, along with
  some misc fixes.

  And a few msm fixes, one of which is also a bit large.

  But nothing in here seems insane or crazy for this stage, just more
  than I'd like"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (33 commits)
  drm/msm/mdp5: release SMB (shared memory blocks) in various cases
  drm/msm: change to uninterruptible wait in atomic commit
  drm/msm: mdp4: Fix drm_framebuffer dereference crash
  drm/msm: fix msm_gem_prime_get_sg_table()
  drm/amdgpu: add new parameter to seperate map and unmap
  drm/amdgpu: hdp_flush is not needed for inside IB
  drm/amdgpu: different emit_ib for gfx and compute
  drm/amdgpu: information leak in amdgpu_info_ioctl()
  drm/amdgpu: clean up init sequence for failures
  drm/radeon/combios: add some validation of lvds values
  drm/radeon: rework audio modeset to handle non-audio hdmi features
  drm/radeon: rework audio detect (v4)
  drm/amdgpu: Drop drm/ prefix for including drm.h in amdgpu_drm.h
  drm/radeon: Drop drm/ prefix for including drm.h in radeon_drm.h
  drm/nouveau/nouveau/ttm: fix tiled system memory with Maxwell
  drm/nouveau/kms/nv50-: guard against enabling cursor on disabled heads
  drm/nouveau/fbcon/g80: reduce PUSH_SPACE alloc, fire ring on accel init
  drm/nouveau/fbcon/gf100-: reduce RING_SPACE allocation
  drm/nouveau/fbcon/nv11-: correctly account for ring space usage
  drm/nouveau/bios: add proper support for opcode 0x59
  ...

This reverts commit b9855f03.
The patch break existing DMA usage case. For example, audio SOC
dmaengine never release channel and cause virt-dma to cache too
much memory in descriptor to exhaust system memory.
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Commit 6f166312 ("dmaengine: mv_xor: add support for a38x command
in descriptor mode") introduced the support for a feature that
appeared in Armada 38x: specifying the operation to be performed in a
per-descriptor basis rather than globally per channel.

However, when doing so, it changed the function mv_chan_set_mode() to
use:

  if (IS_ENABLED(__BIG_ENDIAN))

instead of:

  #if defined(__BIG_ENDIAN)

While IS_ENABLED() is perfectly fine for CONFIG_* symbols, it is not
for other symbols such as __BIG_ENDIAN that is provided directly by
the compiler. Consequently, the commit broke support for big-endian,
as the XOR_DESCRIPTOR_SWAP flag was not set in the XOR channel
configuration register.

The primarily visible effect was some nasty warnings and failures
appearing during the self-test of the XOR unit:

[    1.197368] mv_xor d0060900.xor: error on chan 0. intr cause 0x00000082
[    1.197393] mv_xor d0060900.xor: config       0x00008440
[    1.197410] mv_xor d0060900.xor: activation   0x00000000
[    1.197427] mv_xor d0060900.xor: intr cause   0x00000082
[    1.197443] mv_xor d0060900.xor: intr mask    0x000003f7
[    1.197460] mv_xor d0060900.xor: error cause  0x00000000
[    1.197477] mv_xor d0060900.xor: error addr   0x00000000
[    1.197491] ------------[ cut here ]------------
[    1.197513] WARNING: CPU: 0 PID: 1 at ../drivers/dma/mv_xor.c:664 mv_xor_interrupt_handler+0x14c/0x170()

See also:

  http://storage.kernelci.org/next/next-20150617/arm-mvebu_v7_defconfig+CONFIG_CPU_BIG_ENDIAN=y/lab-khilman/boot-armada-xp-openblocks-ax3-4.txtSigned-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Fixes: 6f166312 ("dmaengine: mv_xor: add support for a38x command in descriptor mode")
Reviewed-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

There is an overlap in dma ring cmd csr region due to sharing of ethernet
ring cmd csr region. This patch fix the resource overlapping by mapping
the entire dma ring cmd csr region.
Signed-off-by: NRameshwar Prasad Sahu <rsahu@apm.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

This patch adds the missing update of the transfer data width in
at_xdmac_prep_slave_sg().

Indeed, for each item in the scatter-gather list, we check whether the
transfer length is aligned with the data width provided by
dmaengine_slave_config(). If so, we directly use this data width for the
current part of the transfer we are preparing. Otherwise, the data width
is reduced to 8 bits (1 byte). Of course, the actual number of register
accesses must also be updated to match the new data width.

So one chunk was missing in the original patch (see Fixes tag below): the
number of register accesses was correctly set to (len >> fixed_dwidth) in
mbr_ubc but the real data width was not updated in mbr_cfg. Since mbr_cfg
may change for each part of the scatter-gather transfer this also explains
why the original patch used the Descriptor View 2 instead of the
Descriptor View 1.

Let's take the example of a DMA transfer to write 8bit data into an Atmel
USART with FIFOs. When FIFOs are enabled in the USART, its Transmit
Holding Register (THR) works in multidata mode, that is to say that up to
4 8bit data can be written into the THR in a single 32bit access and it is
still possible to write only one data with a 8bit access. To take
advantage of this new feature, the DMA driver was modified to allow
multiple dwidths when doing slave transfers.
For instance, when the total length is 22 bytes, the USART driver splits
the transfer into 2 parts:

First part: 20 bytes transferred through 5 32bit writes into THR
Second part: 2 bytes transferred though 2 8bit writes into THR

For the second part, the data width was first set to 4_BYTES by the USART
driver thanks to dmaengine_slave_config() then at_xdmac_prep_slave_sg()
reduces this data width to 1_BYTE because the 2 byte length is not aligned
with the original 4_BYTES data width. Since the data width is modified,
the actual number of writes into THR must be set accordingly.
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Fixes: 6d3a7d9e ("dmaengine: at_xdmac: allow muliple dwidths when doing slave transfers")
Cc: stable@vger.kernel.org #4.0 and later
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

As claimed by the programmer datasheet and confirmed by the IP designer,
the Block Transfer Size (BTSIZE) bitfield of the Channel x Control A
Register (CTRLAx) always refers to a number of Source Width (SRC_WIDTH)
transfers.

Both the SRC_WIDTH and BTSIZE bitfields can be extacted from the CTRLAx
register to compute the DMA residue. So the 'tx_width' field is useless
and can be removed from the struct at_desc.

Before this patch, atc_prep_slave_sg() was not consistent: BTSIZE was
correctly initialized according to the SRC_WIDTH but 'tx_width' was always
set to reg_width, which was incorrect for MEM_TO_DEV transfers. It led to
bad DMA residue when 'tx_width' != SRC_WIDTH.

Also the 'tx_width' field was mostly set only in the first and last
descriptors. Depending on the kind of DMA transfer, this field remained
uninitialized for intermediate descriptors. The accurate DMA residue was
computed only when the currently processed descriptor was the first or the
last of the chain. This algorithm was a little bit odd. An accurate DMA
residue can always be computed using the SRC_WIDTH and BTSIZE bitfields
in the CTRLAx register.

Finally, the test to check whether the currently processed descriptor is
the last of the chain was wrong: for cyclic transfer, last_desc->lli.dscr
is NOT equal to zero, since set_desc_eol() is never called, but logically
equal to first_desc->txd.phys. This bug has a side effect on the
drivers/tty/serial/atmel_serial.c driver, which uses cyclic DMA transfer
to receive data. Since the DMA residue was wrong each time the DMA
transfer reaches the second (and last) period of the transfer, no more
data were received by the USART driver till the cyclic DMA transfer loops
back to the first period.
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: NTorsten Fleischer <torfl6749@gmail.com>
Tested-by: NJirí Prchal <jiri.prchal@aksignal.cz>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

When using descriptor view 2 or higher, we don't write the configuration
into AT_XDMAC_CC register because this configuration will be fetch from
the descriptor. Unfortunately, the PROT bit is not updated with this
method, we have to do it manually before enabling the channel.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

With the grouping of multi-function devices a non-ATS
capable device might also end up in the same domain as an
IOMMUv2 capable device.
So handle this situation gracefully and don't consider it a
bug anymore.
Tested-by: NOded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

modify_ldt() has questionable locking and does not synchronize
threads.  Improve it: redesign the locking and synchronize all
threads' LDTs using an IPI on all modifications.

This will dramatically slow down modify_ldt in multithreaded
programs, but there shouldn't be any multithreaded programs that
care about modify_ldt's performance in the first place.

This fixes some fallout from the CVE-2015-5157 fixes.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The update_va_mapping hypercall can fail if the VA isn't present
in the guest's page tables.  Under certain loads, this can
result in an OOPS when the target address is in unpopulated vmap
space.

While we're at it, add comments to help explain what's going on.

This isn't a great long-term fix.  This code should probably be
changed to use something like set_memory_ro.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Vrabel <dvrabel@cantab.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/0b0e55b995cda11e7829f140b833ef932fcabe3a.1438291540.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent

Pull EFI fixes from Matt Fleming:

 * Fix an EFI boot issue preventing a Parallels virtual machine from
   booting because the upper 32-bits of the EFI memmap pointer were
   being discarded in setup_e820(). (Dmitry Skorodumov)

 * Validate that the "efi" kernel parameter gets used with an argument,
   otherwise we will oops. (Ricardo Neri)
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pull xfs fixes from Dave Chinner:
 "There are a couple of recently found, long standing remote attribute
  corruption fixes caused by log recovery getting confused after a
  crash, and the new DAX code in XFS (merged in 4.2-rc1) needs to
  actually use the DAX fault path on read faults.

  Summary:

   - remote attribute log recovery corruption fixes

   - DAX page faults need to use direct mappings, not a page cache
     mapping"

* tag 'xfs-for-linus-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: remote attributes need to be considered data
  xfs: remote attribute headers contain an invalid LSN
  xfs: call dax_fault on read page faults for DAX

The newsk returned by sk_clone_lock should hold a get_net()
reference if, and only if, the parent is not a kernel socket
(making this similar to sk_alloc()).

E.g,. for the SYN_RECV path, tcp_v4_syn_recv_sock->..inet_csk_clone_lock
sets up the syn_recv newsk from sk_clone_lock. When the parent (listen)
socket is a kernel socket (defined in sk_alloc() as having
sk_net_refcnt == 0), then the newsk should also have a 0 sk_net_refcnt
and should not hold a get_net() reference.

Fixes: 26abe143 ("net: Modify sk_alloc to not reference count the
      netns of kernel sockets.")
Acked-by: NEric Dumazet <edumazet@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>