The desired_perf is an abstract performance number. Its value should
be in the range of [lowest perf, highest perf] of CPPC.
The correct calculation is
  desired_perf = freq * cppc_highest_perf / cppc_dmi_max_khz

And cppc_cpufreq_set_target() returns if desired_perf is exactly
the same with the old perf.
Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit d352cf47 (cpufreq: conservative: Do not use transition
notifications) overlooked the case when the "frequency step" used
by the conservative governor is small relative to the distances
between the available frequencies and broke the algorithm by
using policy->cur instead of the previously requested frequency
when computing the next one.

As a result, the governor may not be able to go outside of a narrow
range between two consecutive available frequencies.

Fix the problem by making the governor save the previously requested
frequency and select the next one relative that value (unless it is
out of range, in which case policy->cur will be used instead).

Fixes: d352cf47 (cpufreq: conservative: Do not use transition notifications)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.8+ <stable@vger.kernel.org> # 4.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Skip invalid entries when searching the frequency. This fixes cpufreq
at least on loongson2 MIPS board.

Fixes: da0c6dc0 (cpufreq: Handle sorted frequency tables more efficiently)
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.8+ <stable@vger.kernel.org> # 4.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

It looks like the name of struct pstate_adjust_policy was updated
without updating its kerneldoc comment accordingly, so fix that
mistake.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The PID algorithm used by the intel_pstate driver tends to drive
performance to the minimum for workloads with utilization below the
setpoint, which is undesirable, so replace it with a modified
"proportional" algorithm on Atom.

The new algorithm will set the new P-state to be 1.25 times the
available maximum times the (frequency-invariant) utilization during
the previous sampling period except when the target P-state computed
this way is lower than the average P-state during the previous
sampling period.  In the latter case, it will increase the target by
50% of the difference between it and the average P-state to prevent
performance from dropping down too fast in some cases.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Make the comment explaining the meaning of the perf_scaled variable
in get_target_pstate_use_performance() more straightforward.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This is a requirement that MSR MSR_PM_ENABLE must be set to 0x01 before
reading MSR_HWP_CAPABILITIES on a given CPU. If cpufreq init() is
scheduled on a CPU which is not same as policy->cpu or migrates to a
different CPU before calling msr read for MSR_HWP_CAPABILITIES, it
is possible that MSR_PM_ENABLE was not to set to 0x01 on that CPU.
This will cause GP fault. So like other places in this path
rdmsrl_on_cpu should be used instead of rdmsrl.

Moreover the scope of MSR_HWP_CAPABILITIES is on per thread basis, so it
should be read from the same CPU, for which MSR MSR_HWP_REQUEST is
getting set.

dmesg dump or warning:

[   22.014488] WARNING: CPU: 139 PID: 1 at arch/x86/mm/extable.c:50 ex_handler_rdmsr_unsafe+0x68/0x70
[   22.014492] unchecked MSR access error: RDMSR from 0x771
[   22.014493] Modules linked in:
[   22.014507] CPU: 139 PID: 1 Comm: swapper/0 Not tainted 4.7.5+ #1
...
...
[   22.014516] Call Trace:
[   22.014542]  [<ffffffff813d7dd1>] dump_stack+0x63/0x82
[   22.014558]  [<ffffffff8107bc8b>] __warn+0xcb/0xf0
[   22.014561]  [<ffffffff8107bcff>] warn_slowpath_fmt+0x4f/0x60
[   22.014563]  [<ffffffff810676f8>] ex_handler_rdmsr_unsafe+0x68/0x70
[   22.014564]  [<ffffffff810677d9>] fixup_exception+0x39/0x50
[   22.014604]  [<ffffffff8102e400>] do_general_protection+0x80/0x150
[   22.014610]  [<ffffffff817f9ec8>] general_protection+0x28/0x30
[   22.014635]  [<ffffffff81687940>] ? get_target_pstate_use_performance+0xb0/0xb0
[   22.014642]  [<ffffffff810600c7>] ? native_read_msr+0x7/0x40
[   22.014657]  [<ffffffff81688123>] intel_pstate_hwp_set+0x23/0x130
[   22.014660]  [<ffffffff81688406>] intel_pstate_set_policy+0x1b6/0x340
[   22.014662]  [<ffffffff816829bb>] cpufreq_set_policy+0xeb/0x2c0
[   22.014664]  [<ffffffff81682f39>] cpufreq_init_policy+0x79/0xe0
[   22.014666]  [<ffffffff81682cb0>] ? cpufreq_update_policy+0x120/0x120
[   22.014669]  [<ffffffff816833a6>] cpufreq_online+0x406/0x820
[   22.014671]  [<ffffffff8168381f>] cpufreq_add_dev+0x5f/0x90
[   22.014717]  [<ffffffff81530ac8>] subsys_interface_register+0xb8/0x100
[   22.014719]  [<ffffffff816821bc>] cpufreq_register_driver+0x14c/0x210
[   22.014749]  [<ffffffff81fe1d90>] intel_pstate_init+0x39d/0x4d5
[   22.014751]  [<ffffffff81fe13f2>] ? cpufreq_gov_dbs_init+0x12/0x12

Cc: 4.3+ <stable@vger.kernel.org> # 4.3+
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Trival fix, dev_err message is missing a \n, so add it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Trival fix, dev_err messages are missing a \n, so add it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch fixes overflow issue when calculating the desired_perf.

Fixes: ad38677d (cpufreq: CPPC: Force reporting values in KHz to fix user space interface)
Signed-off-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that the cpufreq-dt-platdev is used to create the cpufreq-dt platform
device for all OMAP platforms and the platform code that did it
before has been removed, add ti,am33xx and ti,dra7xx to the machine list
in cpufreq-dt-platdev which had relied on the removed platform code to do
this previously.

Fixes: 7694ca6e (cpufreq: omap: Use generic platdev driver)
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.7+ <stable@vger.kernel.org> # 4.7+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add io_boost percent to current pstate_sample tracepoint.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify the P-state selection algorithm for Atom processors to use
the new SCHED_CPUFREQ_IOWAIT flag instead of the questionable
get_cpu_iowait_time_us() function.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify the schedutil cpufreq governor to boost the CPU
frequency if the SCHED_CPUFREQ_IOWAIT flag is passed to
it via cpufreq_update_util().

If that happens, the frequency is set to the maximum during
the first update after receiving the SCHED_CPUFREQ_IOWAIT flag
and then the boost is reduced by half during each following update.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Looks-good-to: Steve Muckle <smuckle@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Testing indicates that it is possible to improve performace
significantly without increasing energy consumption too much by
teaching cpufreq governors to bump up the CPU performance level if
the in_iowait flag is set for the task in enqueue_task_fair().

For this purpose, define a new cpufreq_update_util() flag
SCHED_CPUFREQ_IOWAIT and modify enqueue_task_fair() to pass that
flag to cpufreq_update_util() in the in_iowait case.  That generally
requires cpufreq_update_util() to be called directly from there,
because update_load_avg() may not be invoked in that case.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Looks-good-to: Steve Muckle <smuckle@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Merge tag 'samsung-defconfig-schedutil-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux into pm-cpufreq-sched

The schedutil cpufreq governor will be switched from tristate to bool. Fix
defconfigs.

* tag 'samsung-defconfig-schedutil-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux:
  ARM: multi_v7_defconfig: Don't attempt to enable schedutil governor as module
  ARM: exynos_defconfig: Don't attempt to enable schedutil governor as module

When CPPC is being used by ACPI on arm64, user space tools such as
cpupower report CPU frequency values from sysfs that are incorrect.

What the driver was doing was reporting the values given by ACPI tables
in whatever scale was used to provide them.  However, the ACPI spec
defines the CPPC values as unitless abstract numbers.  Internal kernel
structures such as struct perf_cap, in contrast, expect these values
to be in KHz.  When these struct values get reported via sysfs, the
user space tools also assume they are in KHz, causing them to report
incorrect values (for example, reporting a CPU frequency of 1MHz when
it should be 1.8GHz).

The downside is that this approach has some assumptions:

   (1) It relies on SMBIOS3 being used, *and* that the Max Frequency
   value for a processor is set to a non-zero value.

   (2) It assumes that all processors run at the same speed, or that
   the CPPC values have all been scaled to reflect relative speed.
   This patch retrieves the largest CPU Max Frequency from a type 4 DMI
   record that it can find.  This may not be an issue, however, as a
   sampling of DMI data on x86 and arm64 indicates there is often only
   one such record regardless.  Since CPPC is relatively new, it is
   unclear if the ACPI ASL will always be written to reflect any sort
   of relative performance of processors of differing speeds.

   (3) It assumes that performance and frequency both scale linearly.

For arm64 servers, this may be sufficient, but it does rely on
firmware values being set correctly.  Hence, other approaches will
be considered in the future.

This has been tested on three arm64 servers, with and without DMI, with
and without CPPC support.
Signed-off-by: Al Stone <ahs3@redhat.com>
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

If a cpufreq driver is registered very early in the boot stage (e.g.
registered from postcore_initcall()), then cpufreq core may generate
kernel warnings for it.

In this case, the CPUs are brought online, then the cpufreq driver is
registered, and then the CPU topology devices are registered. However,
by the time cpufreq_add_dev() gets called, the cpu device isn't stored
in the per-cpu variable (cpu_sys_devices,) which is read by
get_cpu_device().

So the cpufreq core fails to get device for the CPU, for which
cpufreq_add_dev() was called in the first place and we will hit a
WARN_ON(!cpu_dev).

Even if we reuse the 'dev' parameter passed to cpufreq_add_dev() to
avoid that warning, there might be other CPUs online that share the
policy with the cpu for which cpufreq_add_dev() is called. Eventually
get_cpu_device() will return NULL for them as well, and we will hit the
same WARN_ON() again.

In order to fix these issues, change cpufreq core to create links to the
policy for a cpu only when cpufreq_add_dev() is called for that CPU.

Reuse the 'real_cpus' mask to track that as well.

Note that cpufreq_remove_dev() already handles removal of the links for
individual CPUs and cpufreq_add_dev() has aligned with that now.
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

For structure types defined in the same file or local header files, find
top-level static structure declarations that have the following
properties:
1. Never reassigned.
2. Address never taken
3. Not passed to a top-level macro call
4. No pointer or array-typed field passed to a function or stored in a
variable.
Declare structures having all of these properties as const.

Done using Coccinelle.
Based on a suggestion by Joe Perches <joe@perches.com>.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The cpufreq-dt driver is also used for systems with multiple
clock/voltage domains for CPUs, i.e. multiple cpufreq policies in a
system.

And in such cases the platform users may want to enable "governor
tunables per policy". Support that via platform data, as not all users
of the driver would want that behavior.
Reported-by: Juri Lelli <Juri.Lelli@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The cpufreq DT driver also supports systems that have multiple
clock/voltage domains for CPUs, i.e. multiple policy systems.

The description of the Kconfig entry was never updated after the driver
was modified to support such systems, fix it.
Reported-by: Juri Lelli <Juri.Lelli@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This is leftover from an earlier patch which removed the usage of
platform data but forgot to remove this line. Remove it now.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

I am told the cpufreq documentation updates should go to the PM list.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add the compatible string for supporting the generic cpufreq driver on
the Renesas R-Car V2H (r8a7792) SoC.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The cpufreq-stats code can no longer be built as a module, so it now
appears with square brackets in menuconfig.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 1aefc75b (cpufreq: stats: Make the stats code non-modular)
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull x86 fix from Thomas Gleixner:
 "A single fix for an AMD erratum so machines without a BIOS fix work"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/AMD: Apply erratum 665 on machines without a BIOS fix

Pull timer fixes from Thomas Gleixner:
 "Two fixlet from the timers departement:

   - A fix for scheduler stalls in the tick idle code affecting
     NOHZ_FULL kernels

   - A trivial compile fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/nohz: Fix softlockup on scheduler stalls in kvm guest
  clocksource/drivers/atmel-pit: Fix compilation error

Pull device mapper fixes from Mike Snitzer:

 - a stable fix in both DM crypt and DM log-writes for too large bios
   (as generated by bcache)

 - two other stable fixes for DM log-writes

 - a stable fix for a DM crypt bug that could result in freeing pointers
   from uninitialized memory in the tfm allocation error path

 - a DM bufio cleanup to discontinue using create_singlethread_workqueue()

* tag 'dm-4.8-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm bufio: remove use of deprecated create_singlethread_workqueue()
  dm crypt: fix free of bad values after tfm allocation failure
  dm crypt: fix error with too large bios
  dm log writes: fix check of kthread_run() return value
  dm log writes: fix bug with too large bios
  dm log writes: move IO accounting earlier to fix error path

Pull btrfs fixes from Chris Mason:
 "I'm still prepping a set of fixes for btrfs fsync, just nailing down a
  hard to trigger memory corruption.  For now, these are tested and ready."

* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix one bug that process may endlessly wait for ticket in wait_reserve_ticket()
  Btrfs: fix endless loop in balancing block groups
  Btrfs: kill invalid ASSERT() in process_all_refs()

Pull arm64 fixes from Catalin Marinas:
 "arm64 and arm/perf fixes:

   - arm64 fix: debug exception unmasking on the CPU resume path

   - ARM PMU fixes: memory leak on error path and NULL pointer
     dereference"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kernel: Fix unmasked debug exceptions when restoring mdscr_el1
  drivers/perf: arm_pmu: Fix NULL pointer dereference during probe
  drivers/perf: arm_pmu: Fix leak in error path

Pull char/misc driver fixes from Greg KH:
 "Here are a number of small driver fixes for 4.8-rc5.

  The largest thing here is deleting an obsolete driver,
  drivers/misc/bh1780gli.c, as the functionality of it was replaced by
  an iio driver a while ago.

  The other fixes are things that have been reported, or reverts of
  broken stuff (the binder change).  All of these changes have been in
  linux-next for a while with no reported issues"

* tag 'char-misc-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  thunderbolt: Don't declare Falcon Ridge unsupported
  thunderbolt: Add support for INTEL_FALCON_RIDGE_2C controller.
  thunderbolt: Fix resume quirk for Falcon Ridge 4C.
  lkdtm: Mark lkdtm_rodata_do_nothing() notrace
  mei: me: disable driver on SPT SPS firmware
  Revert "android: binder: fix dangling pointer comparison"
  drivers/iio/light/Kconfig: SENSORS_BH1780 cleanup
  android: binder: fix dangling pointer comparison
  misc: delete bh1780 driver

Pull driver core fixes from Greg KH:
 "Here are three small fixes for 4.8-rc5.

  One for sysfs, one for kernfs, and one documentation fix, all for
  reported issues.  All of these have been in linux-next for a while"

* tag 'driver-core-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  sysfs: correctly handle read offset on PREALLOC attrs
  documentation: drivers/core/of: fix name of of_node symlink
  kernfs: don't depend on d_find_any_alias() when generating notifications

Pull staging/IIO driver fixes from Greg KH:
 "Here are a number of small fixes for staging and IIO drivers that
  resolve reported problems.

  Full details are in the shortlog.  All of these have been in
  linux-next with no reported issues"

* tag 'staging-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (35 commits)
  arm: dts: rockchip: add reset node for the exist saradc SoCs
  arm64: dts: rockchip: add reset saradc node for rk3368 SoCs
  iio: adc: rockchip_saradc: reset saradc controller before programming it
  iio: accel: kxsd9: Fix raw read return
  iio: adc: ti_am335x_adc: Increase timeout value waiting for ADC sample
  iio: adc: ti_am335x_adc: Protect FIFO1 from concurrent access
  include/linux: fix excess fence.h kernel-doc notation
  staging: wilc1000: correctly check if associatedsta has not been found
  staging: wilc1000: NULL dereference on error
  staging: wilc1000: txq_event: Fix coding error
  MAINTAINERS: Add file patterns for ion device tree bindings
  MAINTAINERS: Update maintainer entry for wilc1000
  iio: chemical: atlas-ph-sensor: fix typo in val assignment
  iio: fix sched WARNING "do not call blocking ops when !TASK_RUNNING"
  staging: comedi: ni_mio_common: fix AO inttrig backwards compatibility
  staging: comedi: dt2811: fix a precedence bug
  staging: comedi: adv_pci1760: Do not return EINVAL for CMDF_ROUND_DOWN.
  staging: comedi: ni_mio_common: fix wrong insn_write handler
  staging: comedi: comedi_test: fix timer race conditions
  staging: comedi: daqboard2000: bug fix board type matching code
  ...

Pull serial driver fixes from Greg KH:
 "Here are some small serial driver fixes for 4.8-rc5.  One fixes an
  oft-reported build issue with the fintek driver, another reverts a
  patch that was causing problems, one fixes a crash, and some new
  device ids were added.

  All of these have been in linux-next for a while"

* tag 'tty-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250: added acces i/o products quad and octal serial cards
  serial: 8250_mid: fix divide error bug if baud rate is 0
  Revert "tty/serial/8250: use mctrl_gpio helpers"
  8250/fintek: rename IRQ_MODE macro

Pull USB/PHY fixes from Greg KH:
 "Here are some USB and PHY driver fixes for 4.8-rc5

  Nothing major, lots of little fixes for reported bugs, and a build fix
  for a missing .h file that the phy drivers needed.  All of these have
  been in linux-next for a while with no reported issues"

* tag 'usb-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (24 commits)
  usb: musb: Fix locking errors for host only mode
  usb: dwc3: gadget: always decrement by 1
  usb: dwc3: debug: fix ep name on trace output
  usb: gadget: udc: core: don't starve DMA resources
  USB: serial: option: add WeTelecom 0x6802 and 0x6803 products
  USB: avoid left shift by -1
  USB: fix typo in wMaxPacketSize validation
  usb: gadget: Add the gserial port checking in gs_start_tx()
  usb: dwc3: gadget: don't rely on jiffies while holding spinlock
  usb: gadget: fsl_qe_udc: signedness bug in qe_get_frame()
  usb: gadget: function: f_rndis: socket buffer may be NULL
  usb: gadget: function: f_eem: socket buffer may be NULL
  usb: renesas_usbhs: gadget: fix return value check in usbhs_mod_gadget_probe()
  usb: dwc2: Add reset control to dwc2
  usb: dwc3: core: allow device to runtime_suspend several times
  usb: dwc3: pci: runtime_resume child device
  USB: serial: option: add WeTelecom WM-D200
  usb: chipidea: udc: don't touch DP when controller is in host mode
  USB: serial: mos7840: fix non-atomic allocation in write path
  USB: serial: mos7720: fix non-atomic allocation in write path
  ...

In commit 8ead9dd5 ("devpts: more pty driver interface cleanups") I
made devpts_get_priv() just return the dentry->fs_data directly.  And
because I thought it wouldn't happen, I added a warning if you ever saw
a pts node that wasn't on devpts.

And no, that warning never triggered under any actual real use, but you
can trigger it by creating nonsensical pts nodes by hand.

So just revert the warning, and make devpts_get_priv() return NULL for
that case like it used to.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org # 4.6+
Cc: Eric W Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull block fixes from Jens Axboe:
 "A collection of fixes for the nvme over fabrics code"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvme-rdma: Get rid of redundant defines
  nvme-rdma: Get rid of duplicate variable
  nvme: fabrics drivers don't need the nvme-pci driver
  nvme-fabrics: get a reference when reusing a nvme_host structure
  nvme-fabrics: change NQN UUID to big-endian format
  nvme-loop: set sqsize to 0-based value, per spec
  nvme-rdma: fix sqsize/hsqsize per spec
  fabrics: define admin sqsize min default, per spec
  nvmet-rdma: +1 to *queue_size from hsqsize/hrqsize
  nvmet-rdma: Fix use after free
  nvme-rdma: initialize ret to zero to avoid returning garbage