Variables declared in a switch statement before any case statements
cannot be automatically initialized with compiler instrumentation (as
they are not part of any execution flow). With GCC's proposed automatic
stack variable initialization feature, this triggers a warning (and they
don't get initialized). Clang's automatic stack variable initialization
(via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also
doesn't initialize such variables[1]. Note that these warnings (or silent
skipping) happen before the dead-store elimination optimization phase,
so even when the automatic initializations are later elided in favor of
direct initializations, the warnings remain.

To avoid these problems, move such variables into the "case" where
they're used or lift them up into the main function body.

arch/x86/xen/enlighten_pv.c: In function ‘xen_write_msr_safe’:
arch/x86/xen/enlighten_pv.c:904:12: warning: statement will never be executed [-Wswitch-unreachable]
  904 |   unsigned which;
      |            ^~~~~

[1] https://bugs.llvm.org/show_bug.cgi?id=44916Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200220062318.69299-1-keescook@chromium.orgReviewed-by: Juergen Gross <jgross@suse.com>
[boris: made @which an 'unsigned int']
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

The number of empty lines between functions in the xenbus.c is
inconsistent.  This trivial style cleanup commit fixes the file to
consistently place only one empty line.
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

A few of static variables in blkback have 'xen_blkif_' prefix, though it
is unnecessary for static variables.  This commit removes such prefixes.
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Each `blkif` has a free pages pool for the grant mapping.  The size of
the pool starts from zero and is increased on demand while processing
the I/O requests.  If current I/O requests handling is finished or 100
milliseconds has passed since last I/O requests handling, it checks and
shrinks the pool to not exceed the size limit, `max_buffer_pages`.

Therefore, host administrators can cause memory pressure in blkback by
attaching a large number of block devices and inducing I/O.  Such
problematic situations can be avoided by limiting the maximum number of
devices that can be attached, but finding the optimal limit is not so
easy.  Improper set of the limit can results in memory pressure or a
resource underutilization.  This commit avoids such problematic
situations by squeezing the pools (returns every free page in the pool
to the system) for a while (users can set this duration via a module
parameter) if memory pressure is detected.

Discussions
===========

The `blkback`'s original shrinking mechanism returns only pages in the
pool which are not currently be used by `blkback` to the system.  In
other words, the pages that are not mapped with granted pages.  Because
this commit is changing only the shrink limit but still uses the same
freeing mechanism it does not touch pages which are currently mapping
grants.

Once memory pressure is detected, this commit keeps the squeezing limit
for a user-specified time duration.  The duration should be neither too
long nor too short.  If it is too long, the squeezing incurring overhead
can reduce the I/O performance.  If it is too short, `blkback` will not
free enough pages to reduce the memory pressure.  This commit sets the
value as `10 milliseconds` by default because it is a short time in
terms of I/O while it is a long time in terms of memory operations.
Also, as the original shrinking mechanism works for at least every 100
milliseconds, this could be a somewhat reasonable choice.  I also tested
other durations (refer to the below section for more details) and
confirmed that 10 milliseconds is the one that works best with the test.
That said, the proper duration depends on actual configurations and
workloads.  That's why this commit allows users to set the duration as a
module parameter.

Memory Pressure Test
====================

To show how this commit fixes the memory pressure situation well, I
configured a test environment on a xen-running virtualization system.
On the `blkfront` running guest instances, I attach a large number of
network-backed volume devices and induce I/O to those.  Meanwhile, I
measure the number of pages that swapped in (pswpin) and out (pswpout)
on the `blkback` running guest.  The test ran twice, once for the
`blkback` before this commit and once for that after this commit.  As
shown below, this commit has dramatically reduced the memory pressure:

                pswpin  pswpout
    before      76,672  185,799
    after          867    3,967

Optimal Aggressive Shrinking Duration
-------------------------------------

To find a best squeezing duration, I repeated the test with three
different durations (1ms, 10ms, and 100ms).  The results are as below:

    duration    pswpin  pswpout
    1           707     5,095
    10          867     3,967
    100         362     3,348

As expected, the memory pressure decreases as the duration increases,
but the reduction become slow from the `10ms`.  Based on this results, I
chose the default duration as 10ms.

Performance Overhead Test
=========================

This commit could incur I/O performance degradation under severe memory
pressure because the squeezing will require more page allocations per
I/O.  To show the overhead, I artificially made a worst-case squeezing
situation and measured the I/O performance of a `blkfront` running
guest.

For the artificial squeezing, I set the `blkback.max_buffer_pages` using
the `/sys/module/xen_blkback/parameters/max_buffer_pages` file.  In this
test, I set the value to `1024` and `0`.  The `1024` is the default
value.  Setting the value as `0` is same to a situation doing the
squeezing always (worst-case).

If the underlying block device is slow enough, the squeezing overhead
could be hidden.  For the reason, I use a fast block device, namely the
rbd[1]:

    # xl block-attach guest phy:/dev/ram0 xvdb w

For the I/O performance measurement, I run a simple `dd` command 5 times
directly to the device as below and collect the 'MB/s' results.

    $ for i in {1..5}; do dd if=/dev/zero of=/dev/xvdb \
                             bs=4k count=$((256*512)); sync; done

The results are as below.  'max_pgs' represents the value of the
`blkback.max_buffer_pages` parameter.

    max_pgs   Min       Max       Median     Avg    Stddev
    0         417       423       420        419.4  2.5099801
    1024      414       425       416        417.8  4.4384682
    No difference proven at 95.0% confidence

In short, even worst case squeezing on ramdisk based fast block device
makes no visible performance degradation.  Please note that this is just
a very simple and minimal test.  On systems using super-fast block
devices and a special I/O workload, the results might be different.  If
you have any doubt, test on your machine with your workload to find the
optimal squeezing duration for you.

[1] https://www.kernel.org/doc/html/latest/admin-guide/blockdev/ramdisk.htmlReviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

A driver's 'reclaim_memory' callback can race with 'probe' or 'remove'
because it will be called whenever memory pressure is detected.  To
avoid such race, this commit embeds a spinlock in each 'xenbus_device'
and make 'xenbus' to hold the lock while the corresponded callbacks are
running.
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Granting pages consumes backend system memory.  In systems configured
with insufficient spare memory for those pages, it can cause a memory
pressure situation.  However, finding the optimal amount of the spare
memory is challenging for large systems having dynamic resource
utilization patterns.  Also, such a static configuration might lack
flexibility.

To mitigate such problems, this commit adds a memory reclaim callback to
'xenbus_driver'.  If a memory pressure is detected, 'xenbus' requests
every backend driver to volunarily release its memory.

Note that it would be able to improve the callback facility for more
sophisticated handlings of general pressures.  For example, it would be
possible to monitor the memory consumption of each device and issue the
release requests to only devices which causing the pressure.  Also, the
callback could be extended to handle not only memory, but general
resources.  Nevertheless, this version of the implementation defers such
sophisticated goals as a future work.
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Commit d3eeb1d7 ("xen/gntdev: use mmu_interval_notifier_insert")
missed a test for use_ptemod when calling mmu_interval_read_begin(). Fix
that.

Fixes: d3eeb1d7 ("xen/gntdev: use mmu_interval_notifier_insert")
CC: stable@vger.kernel.org # 5.5
Reported-by: Ilpo Järvinen <ilpo.jarvinen@cs.helsinki.fi>
Tested-by: Ilpo Järvinen <ilpo.jarvinen@cs.helsinki.fi>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Juergen Gross <jgross@suse.com>

Commit 3aa6c19d ("xen/balloon: Support xend-based toolstack")
tried to fix a regression with running on rather ancient Xen versions.
Unfortunately the fix was based on the assumption that xend would
just use another Xenstore node, but in reality only some downstream
versions of xend are doing that. The upstream xend does not write
that Xenstore node at all, so the problem must be fixed in another
way.

The easiest way to achieve that is to fall back to the behavior
before commit 96edd61d ("xen/balloon: don't online new memory
initially") in case the static memory maximum can't be read.

This is achieved by setting static_max to the current number of
memory pages known by the system resulting in target_diff becoming
zero.

Fixes: 3aa6c19d ("xen/balloon: Support xend-based toolstack")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <stable@vger.kernel.org> # 4.13
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

QEMU running in a stubdom needs to be able to set INTX_DISABLE, and the
MSI(-X) enable flags in the PCI config space. This adds an attribute
'allow_interrupt_control' which when set for a PCI device allows writes
to this flag(s). The toolstack will need to set this for stubdoms.
When enabled, guest (stubdomain) will be allowed to set relevant enable
flags, but only one at a time - i.e. it refuses to enable more than one
of INTx, MSI, MSI-X at a time.

This functionality is needed only for config space access done by device
model (stubdomain) serving a HVM with the actual PCI device. It is not
necessary and unsafe to enable direct access to those bits for PV domain
with the device attached. For PV domains, there are separate protocol
messages (XEN_PCI_OP_{enable,disable}_{msi,msix}) for this purpose.
Those ops in addition to setting enable bits, also configure MSI(-X) in
dom0 kernel - which is undesirable for PCI passthrough to HVM guests.

This should not introduce any new security issues since a malicious
guest (or stubdom) can already generate MSIs through other ways, see
[1] page 8. Additionally, when qemu runs in dom0, it already have direct
access to those bits.

This is the second iteration of this feature. First was proposed as a
direct Xen interface through a new hypercall, but ultimately it was
rejected by the maintainer, because of mixing pciback and hypercalls for
PCI config space access isn't a good design. Full discussion at [2].

[1]: https://invisiblethingslab.com/resources/2011/Software%20Attacks%20on%20Intel%20VT-d.pdf
[2]: https://xen.markmail.org/thread/smpgpws4umdzizze

[part of the commit message and sysfs handling]
Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
[the rest]
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
[boris: A few small changes suggested by Roger, some formatting changes]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Pull RISC-V fixes from Paul Walmsley:
 "Two fixes for RISC-V:

   - Clear FP registers during boot when FP support is present, rather
     than when they aren't present

   - Move the header files associated with the SiFive L2 cache
     controller to drivers/soc (where the code was recently moved)"

* tag 'riscv/for-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Fixup obvious bug for fp-regs reset
  riscv: move sifive_l2_cache.h to include/soc

CSR_MISA is defined in Privileged Architectures' spec: 3.1.1 Machine
ISA Register misa. Every bit:1 indicate a feature, so we should beqz
reset_done when there is no F/D bit in csr_misa register.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
[paul.walmsley@sifive.com: fix typo in commit message]
Fixes: 9e806356 ("riscv: clear the instruction cache and all registers when booting")
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

The commit 9209fb51 ("riscv: move sifive_l2_cache.c to drivers/soc")
moves the sifive L2 cache driver to driver/soc. It did not move the
header file along with the driver. Therefore this patch moves the header
file to driver/soc
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
[paul.walmsley@sifive.com: updated to fix the include guard]
Fixes: 9209fb51 ("riscv: move sifive_l2_cache.c to drivers/soc")
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

Pull iommu fixes from Joerg Roedel:

 - Two fixes for VT-d and generic IOMMU code to fix teardown on error
   handling code paths.

 - Patch for the Intel VT-d driver to fix handling of non-PCI devices

 - Fix W=1 compile warning in dma-iommu code

* tag 'iommu-fixes-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/dma: fix variable 'cookie' set but not used
  iommu/vt-d: Unlink device if failed to add to group
  iommu: Remove device link to group on failure
  iommu/vt-d: Fix adding non-PCI devices to Intel IOMMU

Pull i2c fixes from Wolfram Sang:
 "Two driver bugfixes, a documentation fix, and a removal of a spec
  violation for the bus recovery algorithm in the core"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: fix bus recovery stop mode timing
  i2c: bcm2835: Store pointer to bus clock
  dt-bindings: i2c: at91: fix i2c-sda-hold-time-ns documentation for sam9x60
  i2c: at91: fix clk_offset for sam9x60

Pull thread fixes from Christian Brauner:
 "This contains a series of patches to fix CLONE_SETTLS when used with
  clone3().

  The clone3() syscall passes the tls argument through struct clone_args
  instead of a register. This means, all architectures that do not
  implement copy_thread_tls() but still support CLONE_SETTLS via
  copy_thread() expecting the tls to be located in a register argument
  based on clone() are currently unfortunately broken. Their tls value
  will be garbage.

  The patch series fixes this on all architectures that currently define
  __ARCH_WANT_SYS_CLONE3. It also adds a compile-time check to ensure
  that any architecture that enables clone3() in the future is forced to
  also implement copy_thread_tls().

  My ultimate goal is to get rid of the copy_thread()/copy_thread_tls()
  split and just have copy_thread_tls() at some point in the not too
  distant future (Maybe even renaming copy_thread_tls() back to simply
  copy_thread() once the old function is ripped from all arches). This
  is dependent now on all arches supporting clone3().

  While all relevant arches do that now there are still four missing:
  ia64, m68k, sh and sparc. They have the system call reserved, but not
  implemented. Once they all implement clone3() we can get rid of
  ARCH_WANT_SYS_CLONE3 and HAVE_COPY_THREAD_TLS.

  This series also includes a minor fix for the arm64 uapi headers which
  caused __NR_clone3 to be missing from the exported user headers.

  Unfortunately the series came in a little late especially given that
  it touches a range of architectures. Due to the holidays not all arch
  maintainers responded in time probably due to their backlog. Will and
  Arnd have thankfully acked the arm specific changes.

  Given that the changes are straightforward and rather minimal combined
  with the fact the that clone3() with CLONE_SETTLS is broken I decided
  to send them post rc3 nonetheless"

* tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  um: Implement copy_thread_tls
  clone3: ensure copy_thread_tls is implemented
  xtensa: Implement copy_thread_tls
  riscv: Implement copy_thread_tls
  parisc: Implement copy_thread_tls
  arm: Implement copy_thread_tls
  arm64: Implement copy_thread_tls
  arm64: Move __ARCH_WANT_SYS_CLONE3 definition to uapi headers

Pull HID fix from Jiri Kosina:
 "A regression fix for EPOLLOUT handling in hidraw and uhid"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  HID: hidraw, uhid: Always report EPOLLOUT

Pull USB/PHY fixes from Greg KH:
 "Here are a number of USB and PHY driver fixes for 5.5-rc6

  Nothing all that unusual, just the a bunch of small fixes for a lot of
  different reported issues. The PHY driver fixes are in here as they
  interacted with the usb drivers.

  Full details of the patches are in the shortlog, and all of these have
  been in linux-next with no reported issues"

* tag 'usb-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (24 commits)
  usb: missing parentheses in USE_NEW_SCHEME
  usb: ohci-da8xx: ensure error return on variable error is set
  usb: musb: Disable pullup at init
  usb: musb: fix idling for suspend after disconnect interrupt
  usb: typec: ucsi: Fix the notification bit offsets
  USB: Fix: Don't skip endpoint descriptors with maxpacket=0
  USB-PD tcpm: bad warning+size, PPS adapters
  phy/rockchip: inno-hdmi: round clock rate down to closest 1000 Hz
  usb: chipidea: host: Disable port power only if previously enabled
  usb: cdns3: should not use the same dev_id for shared interrupt handler
  usb: dwc3: gadget: Fix request complete check
  usb: musb: dma: Correct parameter passed to IRQ handler
  usb: musb: jz4740: Silence error if code is -EPROBE_DEFER
  usb: udc: tegra: select USB_ROLE_SWITCH
  USB: core: fix check for duplicate endpoints
  phy: cpcap-usb: Drop extra write to usb2 register
  phy: cpcap-usb: Improve host vs docked mode detection
  phy: cpcap-usb: Prevent USB line glitches from waking up modem
  phy: mapphone-mdm6600: Fix uninitialized status value regression
  phy: cpcap-usb: Fix flakey host idling and enumerating of devices
  ...

Pull char/misc fix from Greg KH:
 "Here is a single fix, for the chrdev core, for 5.5-rc6

  There's been a long-standing race condition triggered by syzbot, and
  occasionally real people, in the chrdev open() path. Will finally took
  the time to track it down and fix it for real before the holidays.

  Here's that one patch, it's been in linux-next for a while with no
  reported issues and it does fix the reported problem"

* tag 'char-misc-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  chardev: Avoid potential use-after-free in 'chrdev_open()'

Pull staging fixes from Greg KH:
 "Here are some small staging driver fixes for 5.5-rc6.

  Nothing major here, just some small fixes for a comedi driver, the
  vt6656 driver, and a new device id for the rtl8188eu driver.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: rtl8188eu: Add device code for TP-Link TL-WN727N v5.21
  staging: comedi: adv_pci1710: fix AI channels 16-31 for PCI-1713
  staging: vt6656: set usb_set_intfdata on driver fail.
  staging: vt6656: remove bool from vnt_radio_power_on ret
  staging: vt6656: limit reg output to block size
  staging: vt6656: correct return of vnt_init_registers.
  staging: vt6656: Fix non zero logical return of, usb_control_msg

Pull tty/serial fixes from Greg KH:
 "Here are two tty/serial driver fixes for 5.5-rc6.

  The first fixes a much much reported issue with a previous tty port
  link patch that is in your tree, and the second fixes a problem where
  the serdev driver would claim ACPI devices that it shouldn't be
  claiming.

  Both have been in linux-next for a while with no reported issues"

* tag 'tty-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serdev: Don't claim unsupported ACPI serial devices
  tty: always relink the port

Pull block fixes from Jens Axboe:
 "A few fixes that should go into this round.

  This pull request contains two NVMe fixes via Keith, removal of a dead
  function, and a fix for the bio op for read truncates (Ming)"

* tag 'block-5.5-2020-01-10' of git://git.kernel.dk/linux-block:
  nvmet: fix per feat data len for get_feature
  nvme: Translate more status codes to blk_status_t
  fs: move guard_bio_eod() after bio_set_op_attrs
  block: remove unused mp_bvec_last_segment

Pull io_uring fix from Jens Axboe:
 "Single fix for this series, fixing a regression with the short read
  handling.

  This just removes it, as it cannot safely be done for all cases"

* tag 'io_uring-5.5-2020-01-10' of git://git.kernel.dk/linux-block:
  io_uring: remove punt of short reads to async context

Pull MTD fixes from Miquel Raynal:
 "MTD:
   - sm_ftl: Fix NULL pointer warning.

  Raw NAND:
   - Cadence: fix compile testing.
   - STM32: Avoid locking.

  Onenand:
   - Fix several sparse/build warnings.

  SPI-NOR:
   - Add a flag to fix interaction with Micron parts"

* tag 'mtd/fixes-for-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: spi-nor: Fix the writing of the Status Register on micron flashes
  mtd: sm_ftl: fix NULL pointer warning
  mtd: onenand: omap2: Pass correct flags for prep_dma_memcpy
  mtd: onenand: samsung: Fix iomem access with regular memcpy
  mtd: onenand: omap2: Fix errors in style
  mtd: cadence: Fix cast to pointer from integer of different size warning
  mtd: rawnand: stm32_fmc2: avoid to lock the CPU bus

Pull sound fixes from Takashi Iwai:
 "A few piled ASoC fixes and usual HD-audio and USB-audio fixups. Some
  of them are for ASoC core error-handling"

* tag 'sound-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda: enable regmap internal locking
  ALSA: hda/realtek - Add quirk for the bass speaker on Lenovo Yoga X1 7th gen
  ALSA: hda/realtek - Set EAPD control to default for ALC222
  ALSA: usb-audio: Apply the sample rate quirk for Bose Companion 5
  ALSA: hda/realtek - Add new codec supported for ALCS1200A
  ASoC: Intel: boards: Fix compile-testing RT1011/RT5682
  ASoC: SOF: imx8: Fix dsp_box offset
  ASoC: topology: Prevent use-after-free in snd_soc_get_pcm_runtime()
  ASoC: fsl_audmix: add missed pm_runtime_disable
  ASoC: stm32: spdifrx: fix input pin state management
  ASoC: stm32: spdifrx: fix race condition in irq handler
  ASoC: stm32: spdifrx: fix inconsistent lock state
  ASoC: core: Fix access to uninitialized list heads
  ASoC: soc-core: Set dpcm_playback / dpcm_capture
  ASoC: SOF: imx8: fix memory allocation failure check on priv->pd_dev
  ASoC: SOF: Intel: hda: hda-dai: fix oops on hda_link .hw_free
  ASoC: SOF: fix fault at driver unload after failed probe

Pull thermal fix from Daniel Lezcano:
 "Fix backward compatibility with old DTBs on QCOM tsens (Amit
  Kucheria)"

* tag 'thermal-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux:
  drivers: thermal: tsens: Work with old DTBs

Pull power management fixes from Rafael Wysocki:
 "Prevent the cpufreq-dt driver from probing Tegra20/30 (Dmitry
  Osipenko) and prevent the Intel RAPL power capping driver from
  crashing during CPU initialization due to a NULL pointer dereference
  if the processor model in use is not known to it (Harry Pan)"

* tag 'pm-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  powercap: intel_rapl: add NULL pointer check to rapl_mmio_cpu_online()
  cpufreq: dt-platdev: Blacklist NVIDIA Tegra20 and Tegra30 SoCs

The existing implementation for the get_feature admin-cmd does not
use per-feature data len. This patch introduces a new helper function
nvmet_feat_data_len(), which is used to calculate per feature data len.
Right now we only set data len for fid 0x81 (NVME_FEAT_HOST_ID).

Fixes: commit e9061c39 ("nvmet: Remove the data_len field from the nvmet_req struct")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Amit Engel <amit.engel@dell.com>
[endiness, naming, and kernel style fixes]
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Decode interrupted command and not ready namespace nvme status codes to
BLK_STS_TARGET. These are not generic IO errors and should use a non-path
specific error so that it can use the non-failover retry path.
Reported-by: John Meneghini <John.Meneghini@netapp.com>
Cc: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

hidraw and uhid device nodes are always available for writing so we should
always report EPOLLOUT and EPOLLWRNORM bits, not only in the cases when
there is nothing to read.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: be54e746 ("HID: uhid: Fix returning EPOLLOUT from uhid_char_poll")
Fixes: 9f3b61dc ("HID: hidraw: Fix returning EPOLLOUT from hidraw_poll")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

* powercap:
  powercap: intel_rapl: add NULL pointer check to rapl_mmio_cpu_online()

Pull pstore fix from Kees Cook:
 "Cengiz Can forwarded a Coverity report about more problems with a rare
  pstore initialization error path, so the allocation lifetime was
  rearranged to avoid needing to share the kfree() responsibilities
  between caller and callee"

* tag 'pstore-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Regularize prz label allocation lifetime

Pull drm fixes from Dave Airlie:
 "Pre-LCA pull request I'm not sure how things will look next week,
  myself and Daniel are at LCA and I'm speaking quite late, so if I get
  my talk finished I'll probably process fixes.

  This week has a bunch of i915 fixes, some amdgpu fixes, one sun4i, one
  core MST, and one core fb_helper fix. More details below:

  core:
   - mst Fix NO_STOP_BIT bit offset (Wayne)

  fb_helper:
   - fb_helper: Fix bits_per_pixel param set behavior to round up
     (Geert)

  sun4i:
   - Fix RGB_DIV clock min divider on old hardware (Chen-Yu)

  amdgpu:
   - Stability fix for raven
   - Reduce pixel encoding to if max clock is exceeded on HDMI to allow
     additional high res modes
   - enable DRIVER_SYNCOBJ_TIMELINE for amdgpu

  i915:
   - Fix GitLab issue #446 causing GPU hangs: Do not restore invalid RS
     state
   - Fix GitLab issue #846: Restore coarse power gating that was
     disabled by initial RC66 context corruption security fixes.
   - Revert f6ec9483 ("drm/i915: extend audio CDCLK>=2*BCLK
     constraint to more platforms") to avoid screen flicker
   - Fix to fill in unitialized uabi_instance in virtual engine uAPI
   - Add two missing W/As for ICL and EHL"

* tag 'drm-fixes-2020-01-10' of git://anongit.freedesktop.org/drm/drm:
  drm/amdgpu: add DRIVER_SYNCOBJ_TIMELINE to amdgpu
  drm/amd/display: Reduce HDMI pixel encoding if max clock is exceeded
  Revert "drm/amdgpu: Set no-retry as default."
  drm/fb-helper: Round up bits_per_pixel if possible
  drm/sun4i: tcon: Set RGB DCLK min. divider based on hardware model
  drm/i915/dp: Disable Port sync mode correctly on teardown
  drm/i915: Add Wa_1407352427:icl,ehl
  drm/i915: Add Wa_1408615072 and Wa_1407596294 to icl,ehl
  drm/i915/gt: Restore coarse power gating
  drm/i915/gt: Do not restore invalid RS state
  drm/i915: Limit audio CDCLK>=2*BCLK constraint back to GLK only
  drm/i915/gt: Mark up virtual engine uabi_instance
  drm/dp_mst: correct the shifting in DP_REMOTE_I2C_READ

Pull rdma fixes from Jason Gunthorpe:
 "First RDMA subsystem updates for 5.5-rc. A very small set of fixes,
  most people seem to still be recovering from December!

  Five small driver fixes:

   - Fix error flow with MR allocation in bnxt_re

   - An errata work around for bnxt_re

   - Misuse of the workqueue API in hfi1

   - Protocol error in hfi1

   - Regression in 5.5 related to the mmap rework with i40iw"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  i40iw: Remove setting of VMA private data and use rdma_user_mmap_io
  IB/hfi1: Adjust flow PSN with the correct resync_psn
  IB/hfi1: Don't cancel unused work item
  RDMA/bnxt_re: Fix Send Work Entry state check while polling completions
  RDMA/bnxt_re: Avoid freeing MR resources if dereg fails

Merge tag 'drm-intel-fixes-2020-01-09-1' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

- Fix GitLab issue #446 causing GPU hangs: Do not restore invalid RS state
- Fix GitLab issue #846: Restore coarse power gating that was disabled
  by initial RC66 context corruption security fixes.
- Revert f6ec9483 ("drm/i915: extend audio CDCLK>=2*BCLK constraint to more platforms")
  to avoid screen flicker
- Fix to fill in unitialized uabi_instance in virtual engine uAPI
- Add two missing W/As for ICL and EHL
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200109133458.GA15558@jlahtine-desk.ger.corp.intel.com

Pull GPIO fixes from Linus Walleij:
 "Here is a host of GPIO fixes for the v5.5 series. The ACPI fix is
  especially important, see summary below and in the commit for details:

   - Select GPIOLIB_IRQCHIP on the max77620 GPIO expander

   - Fix context restore in the Zynq driver

   - Create a new ACPI quirk handler for disabling wakeups on
     problematic hardware.

   - Fix a coding style issue on the mockup device"

* tag 'gpio-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpiolib: acpi: Add honor_wakeup module-option + quirk mechanism
  gpiolib: acpi: Turn dmi_system_id table into a generic quirk table
  gpio: zynq: Fix for bug in zynq_gpio_restore_context API
  gpio: max77620: Add missing dependency on GPIOLIB_IRQCHIP
  gpio: mockup: fix coding style

Pull pin control fixes from Linus Walleij:
 "Two fixes for pin control, not much to say about it, it's just regular
  driver fixes:

   - Fix erroneous shift in the Meson driver

   - Make Lochnagar select the GPIOLIB Kconfig symbol"

* tag 'pinctrl-v5.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: meson: Fix wrong shift value when get drive-strength
  pinctrl: lochnagar: select GPIOLIB

Pull input fixes from Dmitry Torokhov:
 "Just a few small fixups here"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: imx_sc_key - only take the valid data from SCU firmware as key state
  Input: add safety guards to input_set_keycode()
  Input: input_event - fix struct padding on sparc64
  Input: uinput - always report EPOLLOUT

The I2C specification states that tsu:sto for standard mode timing must
be at minimum 4us. Pictographically, this is:

SCL: ____/~~~~~~~~~
SDA: _________/~~~~
       ->|    |<- 4us minimum

We are currently waiting 2.5us between asserting SCL and SDA, which is
in violation of the standard. Adjust the timings to ensure that we meet
what is stipulated as the minimum timings to ensure that all devices
correctly interpret the STOP bus transition.

This is more important than trying to generate a square wave with even
duty cycle.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Micron flashes do not support 16 bit writes on the Status Register.
According to micron datasheets, when using the Write Status Register
(01h) command, the chip select should be driven LOW and held LOW until
the eighth bit of the last data byte has been latched in, after which
it must be driven HIGH. If CS is not driven HIGH, the command is not
executed, flag status register error bits are not set, and the write enable
latch remains set to 1. This fixes the lock operations on micron flashes.
Reported-by: John Garry <john.garry@huawei.com>
Fixes: 39d1e334 ("mtd: spi-nor: Fix clearing of QE bit on lock()/unlock()")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Tested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>