Due to lack of maintenance and stall of development for a few years now,
and since no new features will ever be added upstream, remove support
for OX810 and OX820 timer.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230630-topic-oxnas-upstream-remove-v2-3-fb6ab3dea87c@linaro.org

Smatch reports:
drivers/clocksource/timer-cadence-ttc.c:529 ttc_timer_probe()
warn: 'timer_baseaddr' from of_iomap() not released on lines: 498,508,516.

timer_baseaddr may have the problem of not being released after use,
I replaced it with the devm_of_iomap() function and added the clk_put()
function to cleanup the "clk_ce" and "clk_cs".

Fixes: e932900a ("arm: zynq: Use standard timer binding")
Fixes: 70504f31 ("clocksource/drivers/cadence_ttc: Convert init function to return error")
Signed-off-by: Feng Mingxi <m202271825@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230425065611.702917-1-m202271825@hust.edu.cn

Add YAML documentation for the timer which is present on Ralink SoCs.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230620100231.1412582-1-sergio.paracuellos@gmail.com

Current code assigns either the Hyper-V TSC page or MSR-based ref counter
as the sched clock. This may be sub-optimal in two cases. First, if there
is hardware support to ensure consistent TSC frequency across live
migrations and Hyper-V is using that support, the raw TSC is a faster
source of time than the Hyper-V TSC page.  Second, the MSR-based ref
counter is relatively slow because reads require a trap to the hypervisor.
As such, it should never be used as the sched clock. The native sched
clock based on the raw TSC or jiffies is much better.

Rework the sched clock setup so it is set to the TSC page only if
Hyper-V indicates that the TSC may have inconsistent frequency across
live migrations. Also, remove the code that sets the sched clock to
the MSR-based ref counter. In the cases where it is not set, the sched
clock will then be the native sched clock.

As part of the rework, always enable both the TSC page clocksource and
the MSR-based ref counter clocksource. Set the ratings so the TSC page
clocksource is preferred. While the MSR-based ref counter clocksource
is unlikely to ever be the default, having it available for manual
selection is convenient for development purposes.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1687201360-16003-1-git-send-email-mikelley@microsoft.com

Convert Broadcom Kona family timer bindings to DT schema.

Changes during conversion:
  - drop deprecated compatible (it's been deprecated for ~10 years)
Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230618144635.GA22166@standask-GA-A55M-S2HP

Only the imx-gpt timer driver makes use of enum imx_gpt_type that is
otherwise unused. Move its definition into the timer-imx-gpt driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230328100531.879485-3-u.kleine-koenig@pengutronix.de

The clk drivers use none of the symbols defined in <soc/imx/timer.h>.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230328100531.879485-2-u.kleine-koenig@pengutronix.de

When looking at the data structs defining the different behaviours of
the GPT blocks in different SoCs it's not helpful that the same
functions are used with different names.

So drop the cpp defines and use the original names.

This commit was generated using:

	perl -i -e 'my %m; while (<>) { if (/^#define (imx[a-zA-Z0-6_]*)\s(imx[a-zA-Z0-6_]*)/) {$m{$1} = $2; } else { foreach my $f (keys %m) {s/$f/$m{$f}/; } print; } }' drivers/clocksource/timer-imx-gpt.c

This patch has no effect on the generated code.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230328091514.874724-1-u.kleine-koenig@pengutronix.de

This patch moves most part of arch/mips/loongson32/common/time.c
into drivers/clocksource.

Adapt the driver to clocksource framework with devicetree support
and updates Kconfig/Makefile options.
Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230512103724.587760-4-keguang.zhang@gmail.com

Add devicetree binding document for Loongson-1 clocksource.
Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230512103724.587760-3-keguang.zhang@gmail.com

The Loongson1 PWM timer will be moved to clocksource framework.
Then, the old driver is no longer needed.
Remove the deprecated code and update the Kconfig.
Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230512103724.587760-2-keguang.zhang@gmail.com

The use of the pm_sleep_ptr() macro allows the compiler to always see
the dev_pm_ops structure and related functions, while still allowing the
unused code to be removed, without the need for the __maybe_unused
markings.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230618153937.96649-1-paul@crapouillou.net

The trace output for the HRTIMER_MODE_.*_HARD modes is seen as a number
since these modes are not decoded. The author was not aware of the fancy
decoding function which makes the life easier.

Extend decode_hrtimer_mode() with the additional HRTIMER_MODE_.*_HARD
modes.

Fixes: ae6683d8 ("hrtimer: Introduce HARD expiry mode")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230418143854.8vHWQKLM@linutronix.de

The sys_ni_posix_timers() definition causes a warning when the declaration
is missing, so this needs to be added along with the normal syscalls,
outside of the #ifdef.

kernel/time/posix-stubs.c:26:17: error: no previous prototype for 'sys_ni_posix_timers' [-Werror=missing-prototypes]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230607142925.3126422-1-arnd@kernel.org

The ratelimit logic in report_idle_softirq() is broken because the
exit condition is always true:

	static int ratelimit;

	if (ratelimit < 10)
		return false;  ---> always returns here

	ratelimit++;           ---> no chance to run

Make it check for >= 10 instead.

Fixes: 0345691b ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/tencent_5AAA3EEAB42095C9B7740BE62FBF9A67E007@qq.com

Pointers of type void * do not require a type cast when they are assigned
to a real pointer.
Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609182059.4509-1-zeming@nfschina.com

ret is assigned before checked, so it does not need to initialize the
variable
Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609182856.4660-1-zeming@nfschina.com

Commit c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
turns an ifdef CONFIG_HIGH_RES_TIMERS into an conditional on
"IS_ENABLED(CONFIG_HIGHRES_TIMERS)"; note that the new conditional refers
to "HIGHRES_TIMERS" not "HIGH_RES_TIMERS" as before.

Fix this typo introduced in that refactoring.

Fixes: c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609094643.26253-1-lukas.bulwahn@gmail.com

Make it consistent with the TIP tree documentation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.888493625@linutronix.de

Documenting the obvious is just consuming space for no value.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.832240451@linutronix.de

Make the issues vs. SIG_IGN understandable and remove the 15 years old
promise that a proper solution is already on the horizon.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/874jnrdmrq.ffs@tglx

Yet another incomprehensible piece of art.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.724863461@linutronix.de

Replace the word salad.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.672220780@linutronix.de

The comment about timer lifetime at the end of the function is misplaced
and uncomprehensible.

Make it understandable and put it at the right place. Add a new comment
about the visibility of the new timer ID to user space.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.619897296@linutronix.de

The descriptions for common_nsleep() is wrong and common_nsleep_timens()
lacks any form of comment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.567072835@linutronix.de

The documentation of sys_clock_settime() permissions is at a random place
and mostly word salad.

Remove it and add a concise comment into sys_clock_settime().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.514700292@linutronix.de

Document the syscall in detail and with coherent sentences.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.462051641@linutronix.de

Replace another confusing and inaccurate set of comments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.409169321@linutronix.de

The decades old comment about Posix clock resolution is confusing at best.

Remove it and add a proper explanation to sys_clock_getres().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.356427330@linutronix.de

release_posix_timers() is called for cleaning up both hashed and unhashed
timers. The cases are differentiated by an argument and the usage is
hideous.

Seperate the actual free path out and use it for unhashed timers. Provide a
function for hashed timers.

No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.301432503@linutronix.de

All usage of hash_lock is in thread context. No point in using
spin_lock_irqsave()/irqrestore() for a single usage site.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.249063953@linutronix.de

Technically it's not required to set k_itimer::it_signal to NULL on exit()
because there is no other thread anymore which could lookup the timer
concurrently.

Set it to NULL for consistency sake and add a comment to that effect.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.196462644@linutronix.de

k_itimer::it_signal is read lockless in the RCU protected hash lookup, but
it can be written concurrently in the timer_create() and timer_delete()
path. Annotate these places with READ_ONCE() and WRITE_ONCE()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.143596887@linutronix.de

Document how the timer ID validation in the hash table works.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.091081515@linutronix.de

Describe the hash table properly and remove the IDR leftover comments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.038444551@linutronix.de

Explain it better and add the CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y aspect
for completeness.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183312.985681995@linutronix.de

posix_timer_add() tries to allocate a posix timer ID by starting from the
cached ID which was stored by the last successful allocation.

This is done in a loop searching the ID space for a free slot one by
one. The loop has to terminate when the search wrapped around to the
starting point.

But that's racy vs. establishing the starting point. That is read out
lockless, which leads to the following problem:

CPU0	  	      	     	   CPU1
posix_timer_add()
  start = sig->posix_timer_id;
  lock(hash_lock);
  ...				   posix_timer_add()
  if (++sig->posix_timer_id < 0)
      			             start = sig->posix_timer_id;
     sig->posix_timer_id = 0;

So CPU1 can observe a negative start value, i.e. -1, and the loop break
never happens because the condition can never be true:

  if (sig->posix_timer_id == start)
     break;

While this is unlikely to ever turn into an endless loop as the ID space is
huge (INT_MAX), the racy read of the start value caught the attention of
KCSAN and Dmitry unearthed that incorrectness.

Rewrite it so that all id operations are under the hash lock.

Reported-by: syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/87bkhzdn6g.ffs@tglx

itimer_delete() has a retry loop when the timer is concurrently expired. On
non-RT kernels this just spin-waits until the timer callback has completed,
except for posix CPU timers which have HAVE_POSIX_CPU_TIMERS_TASK_WORK
enabled.

In that case and on RT kernels the existing task could live lock when
preempting the task which does the timer delivery.

Replace spin_unlock() with an invocation of timer_wait_running() to handle
it the same way as the other retry loops in the posix timer code.

Fixes: ec8f954a ("posix-timers: Use a callback for cancel synchronization on PREEMPT_RT")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/87v8g7c50d.ffs@tglx

The arch_get_vdso_data() function is defined separately on each architecture,
but only called when CONFIG_TIME_NS is set. If the definition is a global
function, this causes a W=1 warning without TIME_NS:

arch/x86/entry/vdso/vma.c:35:19: error: no previous prototype for 'arch_get_vdso_data' [-Werror=missing-prototypes]

Move the prototype out of the #ifdef block to reliably turn off that
warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230517131102.934196-15-arnd@kernel.org