Merge tag 'v6.6.46' into for/openbmc/dev-6.6

This is the 6.6.46 stable release

clocksource: Scale the watchdog read retries automatically

[ Upstream commit 2ed08e4bc53298db3f87b528cd804cb0cce066a9 ]

On a 8-socket server the TSC is wrongly marked as 'unstable' and disabled
dur

clocksource: Scale the watchdog read retries automatically

[ Upstream commit 2ed08e4bc53298db3f87b528cd804cb0cce066a9 ]

On a 8-socket server the TSC is wrongly marked as 'unstable' and disabled
during boot time on about one out of 120 boot attempts:

clocksource: timekeeping watchdog on CPU227: wd-tsc-wd excessive read-back delay of 153560ns vs. limit of 125000ns,
wd-wd read-back delay only 11440ns, attempt 3, marking tsc unstable
tsc: Marking TSC unstable due to clocksource watchdog
TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
sched_clock: Marking unstable (119294969739, 159204297)<-(125446229205, -5992055152)
clocksource: Checking clocksource tsc synchronization from CPU 319 to CPUs 0,99,136,180,210,542,601,896.
clocksource: Switched to clocksource hpet

The reason is that for platform with a large number of CPUs, there are
sporadic big or huge read latencies while reading the watchog/clocksource
during boot or when system is under stress work load, and the frequency and
maximum value of the latency goes up with the number of online CPUs.

The cCurrent code already has logic to detect and filter such high latency
case by reading the watchdog twice and checking the two deltas. Due to the
randomness of the latency, there is a low probabilty that the first delta
(latency) is big, but the second delta is small and looks valid. The
watchdog code retries the readouts by default twice, which is not
necessarily sufficient for systems with a large number of CPUs.

There is a command line parameter 'max_cswd_read_retries' which allows to
increase the number of retries, but that's not user friendly as it needs to
be tweaked per system. As the number of required retries is proportional to
the number of online CPUs, this parameter can be calculated at runtime.

Scale and enlarge the number of retries according to the number of online
CPUs and remove the command line parameter completely.

[ tglx: Massaged change log and comments ]

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jin Wang <jin1.wang@intel.com>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240221060859.1027450-1-feng.tang@intel.com
Stable-dep-of: f2655ac2c06a ("clocksource: Fix brown-bag boolean thinko in cs_watchdog_read()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Merge branch 'next' into for-linus

Prepare input updates for 5.17 merge window.

Merge tag 'v5.15' into next

Sync up with the mainline to get the latest APIs and DT bindings.

Merge branch 'pruss-fix' into fixes

Merge in a fix for pruss reset issue caused by enabling pruss for am335x.

Merge tag 'v5.15-rc2' into spi-5.15

Linux 5.15-rc2

Merge drm/drm-next into drm-intel-next

Catch-up on 5.15-rc1 and sync with drm-intel-gt-next
to prepare the PXP topic branch.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-intel-gt-next

Close the divergence which has caused patches not to apply and
have a solid baseline for the PXP patches that Rodrigo will send
a topic branch PR for.

Sign

Merge drm/drm-next into drm-intel-gt-next

Close the divergence which has caused patches not to apply and
have a solid baseline for the PXP patches that Rodrigo will send
a topic branch PR for.

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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Merge drm/drm-next into drm-misc-next

Kickstart new drm-misc-next cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge tag 'timers-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
"Updates for timekeeping, timers and related drivers:

Core co

Merge tag 'timers-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
"Updates for timekeeping, timers and related drivers:

Core code:

- Cure a couple of correctness issues in the posix CPU timer code to
prevent that the tick dependency for NOHZ full is kept alive for no
reason.

- Avoid expensive double reprogramming of the clockevent device in
hrtimer_start_range_ns().

- Avoid pointless SMP function calls when the clock was set to avoid
disturbing CPUs which do not have any affected timers queued.

- Make the clocksource watchdog test work correctly when CONFIG_HZ is
less than 100.

Drivers:

- Prefer the ARM architected timer over the Exynos timer which is way
more expensive to access.

- Add device tree bindings for new Ingenic SoCs

- The usual improvements and cleanups all over the place"

* tag 'timers-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
clocksource: Make clocksource watchdog test safe for slow-HZ systems
dt-bindings: timer: Add ABIs for new Ingenic SoCs
clocksource/drivers/fttmr010: Pass around less pointers
clocksource/drivers/mediatek: Optimize systimer irq clear flow on shutdown
clocksource/drivers/ingenic: Use bitfield macro helpers
clocksource/drivers/sh_cmt: Fix wrong setting if don't request IRQ for clock source channel
dt-bindings: timer: convert rockchip,rk-timer.txt to YAML
clocksource/drivers/exynos_mct: Mark MCT device as CLOCK_EVT_FEAT_PERCPU
clocksource/drivers/exynos_mct: Prioritise Arm arch timer on arm64
hrtimer: Unbreak hrtimer_force_reprogram()
hrtimer: Use raw_cpu_ptr() in clock_was_set()
hrtimer: Avoid more SMP function calls in clock_was_set()
hrtimer: Avoid unnecessary SMP function calls in clock_was_set()
hrtimer: Add bases argument to clock_was_set()
time/timekeeping: Avoid invoking clock_was_set() twice
timekeeping: Distangle resume and clock-was-set events
timerfd: Provide timerfd_resume()
hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y case
hrtimer: Ensure timerfd notification for HIGHRES=n
hrtimer: Consolidate reprogramming code
...

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Merge branch 'for-5.15-printk-index' into for-linus

clocksource: Make clocksource watchdog test safe for slow-HZ systems

The clocksource watchdog test sets a local JIFFIES_SHIFT macro and assumes
that HZ is >= 100. For smaller HZ values this shift va

clocksource: Make clocksource watchdog test safe for slow-HZ systems

The clocksource watchdog test sets a local JIFFIES_SHIFT macro and assumes
that HZ is >= 100. For smaller HZ values this shift value is too large and
causes undefined behaviour.

Move the HZ-based definitions of JIFFIES_SHIFT from kernel/time/jiffies.c
to kernel/time/tick-internal.h so the clocksource watchdog test can utilize
them, which makes it work correctly with all HZ values.

[ tglx: Resolved conflicts and massaged changelog ]

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20210812000133.GA402890@paulmck-ThinkPad-P17-Gen-1/

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Merge branch 'perf/urgent' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v5.14-rc6' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next

Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.

Signed-off-by: Maarten Lankhorst <maarten.lankh

Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next

Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

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Merge branch 'fixes-v5.14' into fixes

Merge drm/drm-next into drm-intel-gt-next

Catching up with 5.14-rc1 and also preparing for a
needed common topic branch for the "Minor revid/stepping
and workaround cleanup"

Reference: https://patc

Merge drm/drm-next into drm-intel-gt-next

Catching up with 5.14-rc1 and also preparing for a
needed common topic branch for the "Minor revid/stepping
and workaround cleanup"

Reference: https://patchwork.freedesktop.org/series/92299/
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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Merge drm/drm-next into drm-intel-next

Catching up with 5.14-rc1

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge branch 'cpufreq/cppc-fie' into cpufreq/arm/linux-next

Merge remote-tracking branch 'torvalds/master' into perf/core

To pick up fixes.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'timers-core-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
"Time and clocksource/clockevent related updates:

Core change

Merge tag 'timers-core-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
"Time and clocksource/clockevent related updates:

Core changes:

- Infrastructure to support per CPU "broadcast" devices for per CPU
clockevent devices which stop in deep idle states. This allows us
to utilize the more efficient architected timer on certain ARM SoCs
for normal operation instead of permanentely using the slow to
access SoC specific clockevent device.

- Print the name of the broadcast/wakeup device in /proc/timer_list

- Make the clocksource watchdog more robust against delays between
reading the current active clocksource and the watchdog
clocksource. Such delays can be caused by NMIs, SMIs and vCPU
preemption.

Handle this by reading the watchdog clocksource twice, i.e. before
and after reading the current active clocksource. In case that the
two watchdog reads shows an excessive time delta, the read sequence
is repeated up to 3 times.

- Improve the debug output and add a test module for the watchdog
mechanism.

- Reimplementation of the venerable time64_to_tm() function with a
faster and significantly smaller version. Straight from the source,
i.e. the author of the related research paper contributed this!

Driver changes:

- No new drivers, not even new device tree bindings!

- Fixes, improvements and cleanups and all over the place"

* tag 'timers-core-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
time/kunit: Add missing MODULE_LICENSE()
time: Improve performance of time64_to_tm()
clockevents: Use list_move() instead of list_del()/list_add()
clocksource: Print deviation in nanoseconds when a clocksource becomes unstable
clocksource: Provide kernel module to test clocksource watchdog
clocksource: Reduce clocksource-skew threshold
clocksource: Limit number of CPUs checked for clock synchronization
clocksource: Check per-CPU clock synchronization when marked unstable
clocksource: Retry clock read if long delays detected
clockevents: Add missing parameter documentation
clocksource/drivers/timer-ti-dm: Drop unnecessary restore
clocksource/arm_arch_timer: Improve Allwinner A64 timer workaround
clocksource/drivers/arm_global_timer: Remove duplicated argument in arm_global_timer
clocksource/drivers/arm_global_timer: Make symbol 'gt_clk_rate_change_nb' static
arm: zynq: don't disable CONFIG_ARM_GLOBAL_TIMER due to CONFIG_CPU_FREQ anymore
clocksource/drivers/arm_global_timer: Implement rate compensation whenever source clock changes
clocksource/drivers/ingenic: Rename unreasonable array names
clocksource/drivers/timer-ti-dm: Save and restore timer TIOCP_CFG
clocksource/drivers/mediatek: Ack and disable interrupts on suspend
clocksource/drivers/samsung_pwm: Constify source IO memory
...

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clocksource: Provide kernel module to test clocksource watchdog

When the clocksource watchdog marks a clock as unstable, this might
be due to that clock being unstable or it might be due to delays t

clocksource: Provide kernel module to test clocksource watchdog

When the clocksource watchdog marks a clock as unstable, this might
be due to that clock being unstable or it might be due to delays that
happen to occur between the reads of the two clocks. It would be good
to have a way of testing the clocksource watchdog's ability to
distinguish between these two causes of clock skew and instability.

Therefore, provide a new clocksource-wdtest module selected by a new
TEST_CLOCKSOURCE_WATCHDOG Kconfig option. This module has a single module
parameter named "holdoff" that provides the number of seconds of delay
before testing should start, which defaults to zero when built as a module
and to 10 seconds when built directly into the kernel. Very large systems
that boot slowly may need to increase the value of this module parameter.

This module uses hand-crafted clocksource structures to do its testing,
thus avoiding messing up timing for the rest of the kernel and for user
applications. This module first verifies that the ->uncertainty_margin
field of the clocksource structures are set sanely. It then tests the
delay-detection capability of the clocksource watchdog, increasing the
number of consecutive delays injected, first provoking console messages
complaining about the delays and finally forcing a clock-skew event.
Unexpected test results cause at least one WARN_ON_ONCE() console splat.
If there are no splats, the test has passed. Finally, it fuzzes the
value returned from a clocksource to test the clocksource watchdog's
ability to detect time skew.

This module checks the state of its clocksource after each test, and
uses WARN_ON_ONCE() to emit a console splat if there are any failures.
This should enable all types of test frameworks to detect any such
failures.

This facility is intended for diagnostic use only, and should be avoided
on production systems.

Reported-by: Chris Mason <clm@fb.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Feng Tang <feng.tang@intel.com>
Link: https://lore.kernel.org/r/20210527190124.440372-5-paulmck@kernel.org

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