Reformatted compatibility strings to one valid combination on
each line.
Add FU540-C000 specific device tree bindings to already available
i2-ocores file. This device is available on
HiFive Unleashed Rev A00 board. Move interrupt under optional
property list as this can be optional.

The FU540-C000 SoC from sifive, has an Opencore's I2C block
reimplementation.

The DT compatibility string for this IP is present in HDL and available at.
https://github.com/sifive/sifive-blocks/blob/master/src/main/scala/devices/i2c/I2C.scala#L73Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

If the driver defers probe because of a missing clock, avoid outputting
an error message. The clock will show up eventually.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The commit

  19b07cb4 ("i2c: i801: Register optional lis3lv02d I2C device on Dell machines")

introduced a new check in order to enumerate some slave devices on Dell
machines. Though, it brings a regression on machines where DMI vendor is not set.

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 8 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc4-next-20190613+ #317
 RIP: 0010:strcmp+0xc/0x20

To fix this crash, check if vendor field is present before accessing to it.

Fixes: 19b07cb4 ("i2c: i801: Register optional lis3lv02d I2C device on Dell machines")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The IOP3xx has some elaborate code to directly slam the
GPIO lines multiplexed with I2C down low before enablement,
apparently a workaround for a hardware bug found in the
early chips.

After consulting the developer documentation for IOP80321
and IOP80331 I can clearly see that this may be useful for
IOP80321 family (mach-iop32x) but it is highly dubious for
any 80331 series or later chip: in these chips the lines
are not multiplexed for UARTs.

We convert the code to pass optional GPIO descriptors
and register these only on the 80321-based boards where
it makes sense, optionally obtain them in the driver and
use the gpiod_set_raw_value() to ascertain the line gets
driven low when needed.

The GPIO driver does not give the GPIO chip a reasonable
label so the patch also adds that so that these machine
descriptor tables can be used.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The S3C2410 does some funny dance around its pins:
- First try to call back to the platform to get and control
  some GPIO pins
- If this doesn't work, it tries to get a pin control handle
- If this doesn't work, it retrieves two GPIOs from the device
  tree node and does nothing with them

If we're gonna retrieve two GPIOs and do nothing with them, we
might as well do it using the GPIO descriptor API. When we use
the resource management API, the code gets smaller.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Model the I2C bus clock divider as a part of the Core Clock Framework.
Primarily this removes the clk_get_rate() call from each transfer.
This call causes problems for slave drivers that themselves have
internal clock components that are controlled by an I2C interface.
When the slave's internal clock component is prepared, the prepare
lock is obtained, and it makes calls to the I2C subsystem to
command the hardware to activate the clock.  In order to perform
the I2C transfer, this driver sets the divider, which requires
it to get the parent clock rate, which it does with clk_get_rate().
Unfortunately, this function will try to take the clock prepare
lock, which is already held by the slave's internal clock calls
creating a deadlock.

Modeling the divider in the CCF natively removes this dependency
and the divider value is only set upon changing the bus clock
frequency or changes in the parent clock that cascade down to this
divisor.  This obviates the need to set the divider with every
transfer and avoids the deadlock described above.  It also should
provide better clock debugging and save a few cycles on each
transfer due to not having to recalcuate the divider value.
Signed-off-by: Annaliese McDermond <nh6z@nh6z.net>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Fix checkpatch.pl WARNING for delay of approximately 1msec
in flush i2c FIFO polling loop by using usleep_range(1000, 2000):
WARNING: msleep < 20ms can sleep for up to 20ms; see ...
Documentation/timers/timers-howto.txt
+               msleep(1);
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Fix checkpatch.pl CHECK as follows:
CHECK: spinlock_t definition without comment
+       spinlock_t xfer_lock;
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Fix checkpatch.pl alignment and blank line check(s) in i2c-tegra.c
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Remove variable initializations in functions that
are followed by assignments before use
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Clean up macros by:
1) removing unused macros
2) replace constants by macro BIT()
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Currently we only create an I2C bus for the ports listed in the
device-tree for that master. There's no real reason for this since
we can discover the number of ports the master supports by looking
at the port_max field of the status register.

This patch re-works the bus add logic so that we always create buses
for each port, unless the bus is marked as unavailable in the DT. This
is useful since it ensures that all the buses provided by the CFAM I2C
master are accessible to debug tools.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Dell platform team told us that some (DMI whitelisted) Dell Latitude
machines have ST microelectronics accelerometer at I2C address 0x29.

Presence of that ST microelectronics accelerometer is verified by existence
of SMO88xx ACPI device which represent that accelerometer. Unfortunately
ACPI device does not specify I2C address.

This patch registers lis3lv02d device for selected Dell Latitude machines
at I2C address 0x29 after detection. And for Dell Vostro V131 machine at
I2C address 0x1d which was manually detected.

Finally commit a7ae8195 ("i2c: i801: Allow ACPI SystemIO OpRegion to
conflict with PCI BAR") allowed to use i2c-i801 driver on Dell machines so
lis3lv02d correctly initialize accelerometer.

Tested on Dell Latitude E6440.
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Cypress USB Type-C CCGx controller firmware version 3.1.10
(which is being used in many NVIDIA GPU cards) has known issue of
not triggering interrupt when a USB device is hot plugged to runtime
resume the controller. If any GPU card gets latest kernel with runtime
pm support but does not get latest fixed firmware then also it should
continue to work and therefore a workaround is required to check for
any connector change event.

The workaround is that i2c bus driver will call pm_request_resume()
to runtime resume ucsi_ccg driver. CCG driver will call the ISR
for any connector change event for NVIDIA GPU card and only if it has
old CCG firmware with the known issue.
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Cypress USB Type-C CCGx controller firmware version 3.1.10
(which is being used in many NVIDIA GPU cards) has known issue of
not triggering interrupt when a USB device is hot plugged to runtime
resume the controller. If any GPU card gets latest kernel with runtime
pm support but does not get latest fixed firmware then also it should
continue to work and therefore a workaround is required to check for
any connector change event

The workaround is to request runtime resume of i2c client
which is UCSI Cypress CCGx driver. CCG driver will call the ISR
for any connector change event only if NVIDIA GPU has old
CCG firmware with the known issue.
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The change enables runtime pm support to UCSI CCG driver.
Added ucsi_resume() function to enable notification after
system reusme. Exported both ucsi_resume() and ucsi_send_command()
symbols in ucsi.c for modular build.
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Enable runtime pm support with autosuspend delay of three second.
This is to make sure I2C client device Cypress CCGx has completed
all transaction.
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Added a local variable "send_stop" to simplify "goto" statements.

The "send_stop" handles below two case
1) When first i2c start fails and so i2c stop is not sent before
exiting

2) When i2c stop failed after all transfers and we do not need to
send another stop before exiting.
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This allows drivers to lookup i2c adapters on ACPI based systems similar to
of_get_i2c_adapter_by_node() with DT based systems.
Signed-off-by: Ruslan Babayev <ruslan@babayev.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Depending on MACH_JZ4780 prevent us from creating a generic kernel that
works on more than one MIPS board. Instead, we just depend on MIPS being
set.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

ARCH_BRCMSTB platforms have the BCM2835 I2C controllers, allow
selecting the i2c-bcm2835 driver on such platforms.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add multiple byte read-write support for slave mode.
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use __maybe_unused for runtime PM related functions instead
of #if CONFIG_PM to simply the code.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Pull tracing warning fix from Steven Rostedt:
 "Make the GCC 9 warning for sub struct memset go away.

  GCC 9 now warns about calling memset() on partial structures when it
  goes across multiple fields. This adds a helper for the place in
  tracing that does this type of clearing of a structure"

* tag 'trace-v5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Silence GCC 9 array bounds warning

Pull KVM fixes from Paolo Bonzini:
 "The usual smattering of fixes and tunings that came in too late for
  the merge window, but should not wait four months before they appear
  in a release.

  I also travelled a bit more than usual in the first part of May, which
  didn't help with picking up patches and reports promptly"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (33 commits)
  KVM: x86: fix return value for reserved EFER
  tools/kvm_stat: fix fields filter for child events
  KVM: selftests: Wrap vcpu_nested_state_get/set functions with x86 guard
  kvm: selftests: aarch64: compile with warnings on
  kvm: selftests: aarch64: fix default vm mode
  kvm: selftests: aarch64: dirty_log_test: fix unaligned memslot size
  KVM: s390: fix memory slot handling for KVM_SET_USER_MEMORY_REGION
  KVM: x86/pmu: do not mask the value that is written to fixed PMUs
  KVM: x86/pmu: mask the result of rdpmc according to the width of the counters
  x86/kvm/pmu: Set AMD's virt PMU version to 1
  KVM: x86: do not spam dmesg with VMCS/VMCB dumps
  kvm: Check irqchip mode before assign irqfd
  kvm: svm/avic: fix off-by-one in checking host APIC ID
  KVM: selftests: do not blindly clobber registers in guest asm
  KVM: selftests: Remove duplicated TEST_ASSERT in hyperv_cpuid.c
  KVM: LAPIC: Expose per-vCPU timer_advance_ns to userspace
  KVM: LAPIC: Fix lapic_timer_advance_ns parameter overflow
  kvm: vmx: Fix -Wmissing-prototypes warnings
  KVM: nVMX: Fix using __this_cpu_read() in preemptible context
  kvm: fix compilation on s390
  ...

Pull /dev/random fix from Ted Ts'o:
 "Fix a soft lockup regression when reading from /dev/random in early
  boot"

* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: fix soft lockup when trying to read from an uninitialized blocking pool

Fixes: eb9d1bf0: "random: only read from /dev/random after its pool has received 128 bits"
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Starting with GCC 9, -Warray-bounds detects cases when memset is called
starting on a member of a struct but the size to be cleared ends up
writing over further members.

Such a call happens in the trace code to clear, at once, all members
after and including `seq` on struct trace_iterator:

    In function 'memset',
        inlined from 'ftrace_dump' at kernel/trace/trace.c:8914:3:
    ./include/linux/string.h:344:9: warning: '__builtin_memset' offset
    [8505, 8560] from the object at 'iter' is out of the bounds of
    referenced subobject 'seq' with type 'struct trace_seq' at offset
    4368 [-Warray-bounds]
      344 |  return __builtin_memset(p, c, size);
          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

In order to avoid GCC complaining about it, we compute the address
ourselves by adding the offsetof distance instead of referring
directly to the member.

Since there are two places doing this clear (trace.c and trace_kdb.c),
take the chance to move the workaround into a single place in
the internal header.

Link: http://lkml.kernel.org/r/20190523124535.GA12931@gmail.comSigned-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
[ Removed unnecessary parenthesis around "iter" ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Pull ext4 fixes from Ted Ts'o:
 "Bug fixes (including a regression fix) for ext4"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix dcache lookup of !casefolded directories
  ext4: do not delete unlinked inode from orphan list on failed truncate
  ext4: wait for outstanding dio during truncate in nojournal mode
  ext4: don't perform block validity checks on the journal inode

Pull libnvdimm fixes from Dan Williams:

 - Fix a regression that disabled device-mapper dax support

 - Remove unnecessary hardened-user-copy overhead (>30%) for dax
   read(2)/write(2).

 - Fix some compilation warnings.

* tag 'libnvdimm-fixes-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/pmem: Bypass CONFIG_HARDENED_USERCOPY overhead
  dax: Arrange for dax_supported check to span multiple devices
  libnvdimm: Fix compilation warnings with W=1

Pull tracing fixes from Steven Rostedt:
 "Tom Zanussi sent me some small fixes and cleanups to the histogram
  code and I forgot to incorporate them.

  I also added a small clean up patch that was sent to me a while ago
  and I just noticed it"

* tag 'trace-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kernel/trace/trace.h: Remove duplicate header of trace_seq.h
  tracing: Add a check_val() check before updating cond_snapshot() track_val
  tracing: Check keys for variable references in expressions too
  tracing: Prevent hist_field_var_ref() from accessing NULL tracing_map_elts

Found by visual inspection, this wasn't caught by my xfstest, since it's
effect is ignoring positive dentries in the cache the fallback just goes
to the disk.  it was introduced in the last iteration of the
case-insensitive patch.

d_compare should return 0 when the entries match, so make sure we are
correctly comparing the entire string if the encoding feature is set and
we are on a case-INsensitive directory.

Fixes: b886ee3e ("ext4: Support case-insensitive file name lookups")
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Pull SCSI fixes from James Bottomley:
 "This is the same set of patches sent in the merge window as the final
  pull except that Martin's read only rework is replaced with a simple
  revert of the original change that caused the regression.

  Everything else is an obvious fix or small cleanup"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  Revert "scsi: sd: Keep disk read-only when re-reading partition"
  scsi: bnx2fc: fix incorrect cast to u64 on shift operation
  scsi: smartpqi: Reporting unhandled SCSI errors
  scsi: myrs: Fix uninitialized variable
  scsi: lpfc: Update lpfc version to 12.2.0.2
  scsi: lpfc: add check for loss of ndlp when sending RRQ
  scsi: lpfc: correct rcu unlock issue in lpfc_nvme_info_show
  scsi: lpfc: resolve lockdep warnings
  scsi: qedi: remove set but not used variables 'cdev' and 'udev'
  scsi: qedi: remove memset/memcpy to nfunc and use func instead
  scsi: qla2xxx: Add cleanup for PCI EEH recovery

Pull block fixes from Jens Axboe:

 - NVMe pull request from Keith, with fixes from a few folks.

 - bio and sbitmap before atomic barrier fixes (Andrea)

 - Hang fix for blk-mq freeze and unfreeze (Bob)

 - Single segment count regression fix (Christoph)

 - AoE now has a new maintainer

 - tools/io_uring/ Makefile fix, and sync with liburing (me)

* tag 'for-linus-20190524' of git://git.kernel.dk/linux-block: (23 commits)
  tools/io_uring: sync with liburing
  tools/io_uring: fix Makefile for pthread library link
  blk-mq: fix hang caused by freeze/unfreeze sequence
  block: remove the bi_seg_{front,back}_size fields in struct bio
  block: remove the segment size check in bio_will_gap
  block: force an unlimited segment size on queues with a virt boundary
  block: don't decrement nr_phys_segments for physically contigous segments
  sbitmap: fix improper use of smp_mb__before_atomic()
  bio: fix improper use of smp_mb__before_atomic()
  aoe: list new maintainer for aoe driver
  nvme-pci: use blk-mq mapping for unmanaged irqs
  nvme: update MAINTAINERS
  nvme: copy MTFA field from identify controller
  nvme: fix memory leak for power latency tolerance
  nvme: release namespace SRCU protection before performing controller ioctls
  nvme: merge nvme_ns_ioctl into nvme_ioctl
  nvme: remove the ifdef around nvme_nvm_ioctl
  nvme: fix srcu locking on error return in nvme_get_ns_from_disk
  nvme: Fix known effects
  nvme-pci: Sync queues on reset
  ...

Merge tag 'linux-kselftest-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest fixes from Shuah Khan:

 - Two fixes to regressions introduced in kselftest Makefile test run
   output refactoring work (Kees Cook)

 - Adding Atom support to syscall_arg_fault test (Tong Bo)

* tag 'linux-kselftest-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/timers: Add missing fflush(stdout) calls
  selftests: Remove forced unbuffering for test running
  selftests/x86: Support Atom for syscall_arg_fault test

Pull Devicetree fixes from Rob Herring:

 - Update checkpatch.pl to use DT vendor-prefixes.yaml

 - Fix DT binding references to files converted to DT schema

 - Clean-up Arm CPU binding examples to match schema

 - Add Sifive block versioning scheme documentation

 - Pass binding directory base to validation tools for reference lookups

* tag 'devicetree-fixes-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  checkpatch.pl: Update DT vendor prefix check
  dt: bindings: mtd: replace references to nand.txt with nand-controller.yaml
  dt-bindings: interrupt-controller: arm,gic: Fix schema errors in example
  dt-bindings: arm: Clean up CPU binding examples
  dt: fix refs that were renamed to json with the same file name
  dt-bindings: Pass binding directory to validation tools
  dt-bindings: sifive: describe sifive-blocks versioning

Pule more SPDX updates from Greg KH:
 "Here is another set of reviewed patches that adds SPDX tags to
  different kernel files, based on a set of rules that are being used to
  parse the comments to try to determine that the license of the file is
  "GPL-2.0-or-later".

  Only the "obvious" versions of these matches are included here, a
  number of "non-obvious" variants of text have been found but those
  have been postponed for later review and analysis.

  These patches have been out for review on the linux-spdx@vger mailing
  list, and while they were created by automatic tools, they were
  hand-verified by a bunch of different people, all whom names are on
  the patches are reviewers"

* tag 'spdx-5.2-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (85 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 125
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 123
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 122
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 121
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 120
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 119
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 118
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 116
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 114
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 113
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 112
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 111
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 110
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 106
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 105
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 103
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 101
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 98
  ...

The kernel test robot has reported that the use of __this_cpu_add()
causes bug messages like:

  BUG: using __this_cpu_add() in preemptible [00000000] code: ...

Given the imprecise nature of the count and the possibility of resetting
the count and doing the measurement again, this is not really a big
problem to use the unprotected __this_cpu_*() functions.

To make the preemption checking code happy, the this_cpu_*() functions
will be used if CONFIG_DEBUG_PREEMPT is defined.

The imprecise nature of the locking counts are also documented with
the suggestion that we should run the measurement a few times with the
counts reset in between to get a better picture of what is going on
under the hood.

Fixes: a8654596 ("locking/rwsem: Enable lock event counting")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>