Detecting a timeout is ok, but we also need to assert a STOP command on
the bus in order to prevent it from generating interrupts when there are
no on going transfers.

Example: very long transmission.

1. ocores_xfer: START a transfer
2. ocores_isr : handle byte by byte the transfer
3. ocores_xfer: goes in timeout [[bugfix here]]
4. ocores_xfer: return to I2C subsystem and to the I2C driver
5. I2C driver : it may clean up the i2c_msg memory
6. ocores_isr : receives another interrupt (pending bytes to be
                transferred) but the i2c_msg memory is invalid now

So, since the transfer was too long, we have to detect the timeout and
STOP the transfer.

Another point is that we have a critical region here. When handling the
timeout condition we may have a running IRQ handler. For this reason I
introduce a spinlock.

In order to make easier to understan locking I have:
- added a new function to handle timeout
- modified the current ocores_process() function in order to be protected
  by the new spinlock
Like this it is obvious at first sight that this locking serializes
the execution of ocores_process() and ocores_process_timeout()
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch adds I2C interface timing registers support for
proper bus rate configuration along with meeting the I2C spec
setup and hold times based on the tuning performed on Tegra210,
Tegra186 and Tegra194 platforms.

I2C_INTERFACE_TIMING_0 register contains TLOW and THIGH field
and Tegra I2C controller design uses them as a part of internal
clock divisor.

I2C_INTERFACE_TIMING_1 register contains the setup and hold times
for start and stop conditions.
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Tegra194 allows max of 64K bytes and Tegra186 and prior allows
max of 4K bytes of transfer per packet.

one sec timeout is not enough for transfers more than 10K bytes
at STD bus rate.

This patch updates I2C transfer timeout based on the transfer size
and I2C bus rate to allow enough time during max transfer size at
lower bus speed.
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch adds DMA support for Tegra I2C.

Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
transfer size of the max FIFO depth and DMA mode is used for
transfer size higher than max FIFO depth to save CPU overhead.

PIO mode needs full intervention of CPU to fill or empty FIFO's
and also need to service multiple data requests interrupt for the
same transaction. This adds delay between data bytes of the same
transfer when CPU is fully loaded and some slave devices has
internal timeout for no bus activity and stops transaction to
avoid bus hang. DMA mode is helpful in such cases.

DMA mode is also helpful for Large transfers during downloading or
uploading FW over I2C to some external devices.

Tegra210 and prior Tegra chips use APBDMA driver which is replaced
with GPCDMA on Tegra186 and Tegra194.
This patch uses has_apb_dma flag in hw_feature to differentiate
DMA driver change between Tegra chipset.

APBDMA driver is registered from module-init level and this patch
also has a change to register I2C driver at module-init level
rather than subsys-init to avoid deferring I2C probe till APBDMA
driver is registered.
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Tegra194 supports maximum 64K bytes per packet including 12 bytes of
packet header irrespective of PIO or DMA mode transfer.

This patch updates Tegra194 max write length to account for packet
header size for transfers.

Cc: stable@vger.kernel.org # 4.20+
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Tegra186 and prior supports maximum 4K bytes per packet transfer
including 12 bytes of packet header.

This patch fixes max write length limit to account packet header
size for transfers.

Cc: stable@vger.kernel.org # 4.4+
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Bus clear feature of Tegra I2C controller helps to recover from
bus hang when I2C master loses the bus arbitration due to the
slave device holding SDA LOW continuously for some unknown reasons.

Per I2C specification, the device that held the bus LOW should
release it within 9 clock pulses.

During bus clear operation, Tegra I2C controller sends 9 clock
pulses and terminates the transaction with STOP condition.
Upon successful bus clear operation, bus goes to idle state and
driver retries the transaction.
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch sorts all the include headers alphabetically for the
I2C Tegra driver.
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Pull dmaengine fixes from Vinod Koul:
 - Fix in at_xdmac fr wrongful channel state
 - Fix for imx driver for wrong callback invocation
 - Fix to bcm driver for interrupt race & transaction abort.
 - Fix in dmatest to abort in mapping error

* tag 'dmaengine-fix-5.0-rc6' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dmatest: Abort test in case of mapping error
  dmaengine: bcm2835: Fix abort of transactions
  dmaengine: bcm2835: Fix interrupt race on RT
  dmaengine: imx-dma: fix wrong callback invoke
  dmaengine: at_xdmac: Fix wrongfull report of a channel as in use

Pull x86 fixes from Ingo Molnar:
 "A handful of fixes:

   - Fix an MCE corner case bug/crash found via MCE injection testing

   - Fix 5-level paging boot crash

   - Fix MCE recovery cache invalidation bug

   - Fix regression on Xen guests caused by a recent PMD level mremap
     speedup optimization"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Make set_pmd_at() paravirt aware
  x86/mm/cpa: Fix set_mce_nospec()
  x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 setting
  x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()

Pull irq fixes from Ingo Molnar:
 "irqchip driver fixes: most of them are race fixes for ARM GIC (General
  Interrupt Controller) variants, but also a fix for the ARM MMP
  (Marvell PXA168 et al) irqchip affecting OLPC keyboards"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Fix ITT_entry_size accessor
  irqchip/mmp: Only touch the PJ4 IRQ & FIQ bits on enable/disable
  irqchip/gic-v3-its: Gracefully fail on LPI exhaustion
  irqchip/gic-v3-its: Plug allocation race for devices sharing a DevID
  irqchip/gic-v4: Fix occasional VLPI drop

Pull perf fixes from Ingo Molnar:
 "A couple of kernel side fixes:

   - Fix the Intel uncore driver on certain hardware configurations

   - Fix a CPU hotplug related memory allocation bug

   - Remove a spurious WARN()

  ... plus also a handful of perf tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf script python: Add Python3 support to tests/attr.py
  perf trace: Support multiple "vfs_getname" probes
  perf symbols: Filter out hidden symbols from labels
  perf symbols: Add fallback definitions for GELF_ST_VISIBILITY()
  tools headers uapi: Sync linux/in.h copy from the kernel sources
  perf clang: Do not use 'return std::move(something)'
  perf mem/c2c: Fix perf_mem_events to support powerpc
  perf tests evsel-tp-sched: Fix bitwise operator
  perf/core: Don't WARN() for impossible ring-buffer sizes
  perf/x86/intel: Delay memory deallocation until x86_pmu_dead_cpu()
  perf/x86/intel/uncore: Add Node ID mask

Pull locking fixes from Ingo Molnar:
 "An rtmutex (PI-futex) deadlock scenario fix, plus a locking
  documentation fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Handle early deadlock return correctly
  futex: Fix barrier comment

set_pmd_at() calls native_set_pmd() unconditionally on x86. This was
fine as long as only huge page entries were written via set_pmd_at(),
as Xen pv guests don't support those.

Commit 2c91bd4a ("mm: speed up mremap by 20x on large regions")
introduced a usage of set_pmd_at() possible on pv guests, leading to
failures like:

BUG: unable to handle kernel paging request at ffff888023e26778
#PF error: [PROT] [WRITE]
RIP: e030:move_page_tables+0x7c1/0xae0
move_vma.isra.3+0xd1/0x2d0
__se_sys_mremap+0x3c6/0x5b0
 do_syscall_64+0x49/0x100
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Make set_pmd_at() paravirt aware by just letting it use set_pmd().

Fixes: 2c91bd4a ("mm: speed up mremap by 20x on large regions")
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Cc: sstabellini@kernel.org
Cc: hpa@zytor.com
Cc: bp@alien8.de
Cc: torvalds@linux-foundation.org
Link: https://lkml.kernel.org/r/20190210074056.11842-1-jgross@suse.com

Pull i2c fixes from Wolfram Sang:
 "One PM related driver bugfix and a MAINTAINERS update"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: Update the ocores i2c bus driver maintainer, etc
  i2c: omap: Use noirq system sleep pm ops to idle device for suspend

Pull MIPS fixes from Paul Burton:
 "A batch of MIPS fixes for 5.0, nothing too scary.

   - A workaround for a Loongson 3 CPU bug is the biggest change, but
     still fairly straightforward. It adds extra memory barriers (sync
     instructions) around atomics to avoid a CPU bug that can break
     atomicity.

   - Loongson64 also sees a fix for powering off some systems which
     would incorrectly reboot rather than waiting for the power down
     sequence to complete.

   - We have DT fixes for the Ingenic JZ4740 SoC & the JZ4780-based Ci20
     board, and a DT warning fix for the Nexsys4/MIPSfpga board.

   - The Cavium Octeon platform sees a further fix to the behaviour of
     the pcie_disable command line argument that was introduced in v3.3.

   - The VDSO, introduced in v4.4, sees build fixes for configurations
     of GCC that were built using the --with-fp-32= flag to specify a
     default 32-bit floating point ABI.

   - get_frame_info() sees a fix for configurations with
     CONFIG_KALLSYMS=n, for which it previously always returned an
     error.

   - If the MIPS Coherence Manager (CM) reports an error then we'll now
     clear that error correctly so that the GCR_ERROR_CAUSE register
     will be updated with information about any future errors"

* tag 'mips_fixes_5.0_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  mips: cm: reprime error cause
  mips: loongson64: remove unreachable(), fix loongson_poweroff().
  MIPS: Remove function size check in get_frame_info()
  MIPS: Use lower case for addresses in nexys4ddr.dts
  MIPS: Loongson: Introduce and use loongson_llsc_mb()
  MIPS: VDSO: Include $(ccflags-vdso) in o32,n32 .lds builds
  MIPS: VDSO: Use same -m%-float cflag as the kernel proper
  MIPS: OCTEON: don't set octeon_dma_bar_type if PCI is disabled
  DTS: CI20: Fix bugs in ci20's device tree.
  MIPS: DTS: jz4740: Correct interrupt number of DMA core

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph, fixing namespace locking when
   dealing with the effects log, and a rapid add/remove issue (Keith)

 - blktrace tweak, ensuring requests with -1 sectors are shown (Jan)

 - link power management quirk for a Smasung SSD (Hans)

 - m68k nfblock dynamic major number fix (Chengguang)

 - series fixing blk-iolatency inflight counter issue (Liu)

 - ensure that we clear ->private when setting up the aio kiocb (Mike)

 - __find_get_block_slow() rate limit print (Tetsuo)

* tag 'for-linus-20190209' of git://git.kernel.dk/linux-block:
  blk-mq: remove duplicated definition of blk_mq_freeze_queue
  Blk-iolatency: warn on negative inflight IO counter
  blk-iolatency: fix IO hang due to negative inflight counter
  blktrace: Show requests without sector
  fs: ratelimit __find_get_block_slow() failure message.
  m68k: set proper major_num when specifying module param major_num
  libata: Add NOLPM quirk for SAMSUNG MZ7TE512HMHP-000L1 SSD
  nvme-pci: fix rapid add remove sequence
  nvme: lock NS list changes while handling command effects
  aio: initialize kiocb private in case any filesystems expect it.

Pull mtd fixes from Boris Brezillon:

 - Fix a problem with the imx28 ECC engine

 - Remove a debug trace introduced in 2b6f0090 ("mtd: Check
   add_mtd_device() ret code")

 - Make sure partitions of size 0 can be registered

 - Fix kernel-doc warning in the rawnand core

 - Fix the error path of spinand_init() (missing manufacturer cleanup in
   a few places)

 - Address a problem with the SPI NAND PROGRAM LOAD operation which does
   not work as expected on some parts.

* tag 'mtd/fixes-for-5.0-rc6' of git://git.infradead.org/linux-mtd:
  mtd: rawnand: gpmi: fix MX28 bus master lockup problem
  mtd: Make sure mtd->erasesize is valid even if the partition is of size 0
  mtd: Remove a debug trace in mtdpart.c
  mtd: rawnand: fix kernel-doc warnings
  mtd: spinand: Fix the error/cleanup path in spinand_init()
  mtd: spinand: Handle the case where PROGRAM LOAD does not reset the cache

Pull xen fixes from Juergen Gross:
 "Two very minor fixes: one remove of a #include for an unused header
  and a fix of the xen ML address in MAINTAINERS"

* tag 'for-linus-5.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  MAINTAINERS: unify reference to xen-devel list
  arch/arm/xen: Remove duplicate header

Merge tag 'perf-urgent-for-mingo-5.0-20190205' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

perf trace:

  Arnaldo Carvalho de Melo:

    Fix handling of probe:vfs_getname when the probed routine is
    inlined in multiple places, fixing the collection of the 'filename'
    parameter in open syscalls.

perf test:

  Gustavo A. R. Silva:

    Fix bitwise operator usage in evsel-tp-sched test, which made tat
    test always detect fields as signed.

  Jiri Olsa:

    Filter out hidden symbols from labels, added in systems where the
    annobin plugin is used, such as RHEL8, which, if left in place make
    the DWARF unwind 'perf test' to fail on PPC.

  Tony Jones:

    Fix 'perf_event_attr' tests when building with python3.

perf mem/c2c:

  Ravi Bangoria:

    Fix perf_mem_events on PowerPC.

tools headers UAPI:

  Arnaldo Carvalho de Melo:

    Sync linux/in.h copy from the kernel sources, silencing a perf build warning.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull ARM SoC fixes from Arnd Bergmann:
 "This is a bit larger than normal, as we had not managed to send out a
  pull request before traveling for a week without my signing key.

  There are multiple code fixes for older bugs, all of which should get
  backported into stable kernels:

   - tango: one fix for multiplatform configurations broken on other
     platforms when tango is enabled

   - arm_scmi: device unregistration fix

   - iop32x: fix kernel oops from extraneous __init annotation

   - pxa: remove a double kfree

   - fsl qbman: close an interrupt clearing race

  The rest is the usual collection of smaller fixes for device tree
  files, on the renesas, allwinner, meson, omap, davinci, qualcomm and
  imx platforms.

  Some of these are for compile-time warnings, most are for board
  specific functionality that fails to work because of incorrect
  settings"

* tag 'armsoc-fixes-5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (30 commits)
  ARM: tango: Improve ARCH_MULTIPLATFORM compatibility
  firmware: arm_scmi: provide the mandatory device release callback
  ARM: iop32x/n2100: fix PCI IRQ mapping
  arm64: dts: add msm8996 compatible to gicv3
  ARM: dts: am335x-shc.dts: fix wrong cd pin level
  ARM: dts: n900: fix mmc1 card detect gpio polarity
  ARM: dts: omap3-gta04: Fix graph_port warning
  ARM: pxa: ssp: unneeded to free devm_ allocated data
  ARM: dts: r8a7743: Convert to new LVDS DT bindings
  soc: fsl: qbman: avoid race in clearing QMan interrupt
  arm64: dts: renesas: r8a77965: Enable DMA for SCIF2
  arm64: dts: renesas: r8a7796: Enable DMA for SCIF2
  arm64: dts: renesas: r8a774a1: Enable DMA for SCIF2
  ARM: dts: da850: fix interrupt numbers for clocksource
  dt-bindings: imx8mq: Number clocks consecutively
  arm64: dts: meson: Fix mmc cd-gpios polarity
  ARM: dts: imx6sx: correct backward compatible of gpt
  ARM: dts: imx: replace gpio-key,wakeup with wakeup-source property
  ARM: dts: vf610-bk4: fix incorrect #address-cells for dspi3
  ARM: dts: meson8m2: mxiii-plus: mark the SD card detection GPIO active-low
  ...

Pull arm64 fixes from Will Deacon:
 "Two arm64 fixes for -rc6. They resolve a kernel NULL dereference in
  kexec and bogus kernel page table dumping when userspace is configured
  for 52-bit virtual addressing.

  Summary:

   - Fix kernel oops when attemping kexec_file() with a NULL cmdline

   - Fix page table output in debugfs when ARM64_USER_VA_BITS_52=y"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kexec_file: handle empty command-line
  arm64: ptdump: Don't iterate kernel page tables using PTRS_PER_PXX

Pull powerpc fixes from Michael Ellerman:
 "Just two fixes, both going to stable.

   - Our support for split pmd page table lock had a bug which could
     lead to a crash on mremap() when using the Radix MMU (Power9 only).

   - A fix for the PAPR SCM driver (nvdimm) we added last release, which
     had a bug where we might mis-handle a hypervisor response leading
     to us failing to attach the memory region.

  Thanks to: Aneesh Kumar K.V, Oliver O'Halloran"

* tag 'powerpc-5.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/papr_scm: Use the correct bind address
  powerpc/radix: Fix kernel crash with mremap()

Pull signal fixes from Eric Biederman:
 "This contains four small fixes for signal handling. A missing range
  check, a regression fix, prioritizing signals we have already started
  a signal group exit for, and better detection of synchronous signals.

  The confused decision of which signals to handle failed spectacularly
  when a timer was pointed at SIGBUS and the stack overflowed. Resulting
  in an unkillable process in an infinite loop instead of a SIGSEGV and
  core dump"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Better detection of synchronous signals
  signal: Always notice exiting tasks
  signal: Always attempt to allocate siginfo for SIGSTOP
  signal: Make siginmask safe when passed a signal of 0

Pull SCSI fixes from James Bottomley:
 "This is a set of five minor fixes (although, tecnhincally, the aicxxx
  fix is for a major problem in that the driver won't load without it,
  but I think the fact it's taken us since 4.10 to discover this
  indicates that the user base for these things has declined)"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: cxlflash: Prevent deadlock when adapter probe fails
  Revert "scsi: libfc: Add WARN_ON() when deleting rports"
  scsi: sd_zbc: Fix zone information messages
  scsi: target: make the pi_prot_format ConfigFS path readable
  scsi: aic94xx: fix module loading

Pull IOMMU fix from Joerg Roedel:
 "Intel decided to leave the newly added Scalable Mode Feature
  default-disabled for now. The patch here accomplishes that"

* tag 'iommu-fixes-v5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Leave scalable mode default off

Pull PCI fix from Bjorn Helgaas:
 "Work around Synopsys duplicate Device ID (HAPS USB3, NXP i.MX) that
  breaks PCIe on I.MX SoCs (Thinh Nguyen)"

* tag 'pci-v5.0-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Work around Synopsys duplicate Device ID (HAPS USB3, NXP i.MX)

Pull ACPI fix from Rafael Wysocki:
 "This prevents excessive ACPI debug messages from being printed to the
  kernel log, which has started to happen after one of the recent ACPICA
  commits (Erik Schmauss)"

* tag 'acpi-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: Set debug output flags independent of ACPICA

The latest documentation made it clear that we need to initialize the
TCYC value independently of DMA. The old code used TCYC06 (wrongly) for
non-DMA transfers. The new code sets TCYC up independently from DMA.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

I think it is clear enough if we have the explanation once and make it
clear it is applicable for both SCL and SDA. Reword it a little with
the help of Simon's native language skills :)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We measured the clock on a Lager and an Ebisu board. The new formula
gives better results for both. So after Gen3, switch to this formula for
all Gen2 SoCs.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We could finally measure the clock on an Ebisu board. The new formula
gives way better results, i.e. 100kHz instead of 106kHz and 400kHz
instead of 387kHz. Switch to these formulas for all Gen3 SoCs.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Makes it easier to add new ones.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This augments the CBUS GPIO I2C driver to use GPIO
descriptors for clock, sel and data. We drop the platform
data that was only used for carrying GPIO numbers and
use machine descriptor tables instead.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The listed maintainer has not been responding to emails for a while.
Add myself as a second maintainer.

Add the platform data include file, which was not listed.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

As the prototype has been defined in "include/linux/blk-mq.h", the one
in "block/blk-mq.h" can be removed then.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This is to catch any unexpected negative value of inflight IO counter.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Our test reported the following stack, and vmcore showed that
->inflight counter is -1.

[ffffc9003fcc38d0] __schedule at ffffffff8173d95d
[ffffc9003fcc3958] schedule at ffffffff8173de26
[ffffc9003fcc3970] io_schedule at ffffffff810bb6b6
[ffffc9003fcc3988] blkcg_iolatency_throttle at ffffffff813911cb
[ffffc9003fcc3a20] rq_qos_throttle at ffffffff813847f3
[ffffc9003fcc3a48] blk_mq_make_request at ffffffff8137468a
[ffffc9003fcc3b08] generic_make_request at ffffffff81368b49
[ffffc9003fcc3b68] submit_bio at ffffffff81368d7d
[ffffc9003fcc3bb8] ext4_io_submit at ffffffffa031be00 [ext4]
[ffffc9003fcc3c00] ext4_writepages at ffffffffa03163de [ext4]
[ffffc9003fcc3d68] do_writepages at ffffffff811c49ae
[ffffc9003fcc3d78] __filemap_fdatawrite_range at ffffffff811b6188
[ffffc9003fcc3e30] filemap_write_and_wait_range at ffffffff811b6301
[ffffc9003fcc3e60] ext4_sync_file at ffffffffa030cee8 [ext4]
[ffffc9003fcc3ea8] vfs_fsync_range at ffffffff8128594b
[ffffc9003fcc3ee8] do_fsync at ffffffff81285abd
[ffffc9003fcc3f18] sys_fsync at ffffffff81285d50
[ffffc9003fcc3f28] do_syscall_64 at ffffffff81003c04
[ffffc9003fcc3f50] entry_SYSCALL_64_after_swapgs at ffffffff81742b8e

The ->inflight counter may be negative (-1) if

1) blk-iolatency was disabled when the IO was issued,

2) blk-iolatency was enabled before this IO reached its endio,

3) the ->inflight counter is decreased from 0 to -1 in endio()

In fact the hang can be easily reproduced by the below script,

H=/sys/fs/cgroup/unified/
P=/sys/fs/cgroup/unified/test

echo "+io" > $H/cgroup.subtree_control
mkdir -p $P

echo $$ > $P/cgroup.procs

xfs_io -f -d -c "pwrite 0 4k" /dev/sdg

echo "`cat /sys/block/sdg/dev` target=1000000" > $P/io.latency

xfs_io -f -d -c "pwrite 0 4k" /dev/sdg

This fixes the problem by freezing the queue so that while
enabling/disabling iolatency, there is no inflight rq running.

Note that quiesce_queue is not needed as this only updating iolatency
configuration about which dispatching request_queue doesn't care.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>