The vDSO library should only include the necessary headers required for
a userspace library (UAPI and a minimal set of kernel headers). To make
this possible it is necessary to isolate from the kernel headers the
common parts that are strictly necessary to build the library.
Split const.h into linux and common headers to make the latter suitable
for inclusion in the vDSO library.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200320145351.32292-2-vincenzo.frascino@arm.com
This reverts commit d441dceb5d due to
boot failures.
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
To minimize latency, PREEMPT_RT kernels expires hrtimers in preemptible
softirq context by default. This can be overriden by marking the timer's
expiry with HRTIMER_MODE_HARD.
sched_clock_timer is missing this annotation: if its callback is preempted
and the duration of the preemption exceeds the wrap around time of the
underlying clocksource, sched clock will get out of sync.
Mark the sched_clock_timer for expiry in hard interrupt context.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200309181529.26558-1-a.darwish@linutronix.de
in order to prevent the platform to create another device (Saravana Kannan)
- Remove unused includes from imx family drivers (Anson Huang)
- timer-dm-ti rework to prepare for pwm and suspend support (Lokesh Vutla)
- Fix the rate for the global clock on the pit64b (Claudiu Beznea)
- Fix timer-cs5535 by requesting an irq with non-NULL dev_id (Afzal Mohammed)
- Replace setup_irq() by request_irq() (Afzal Mohammed)
- Add support for the TCU of X1000 (Zhou Yanjie)
- Drop the bogus omap_dm_timer_of_set_source() function (Suman Anna)
- Do not update the counter when updating the period in order to
prevent a disruption when the pwm is used (Lokesh Vutla)
- Improve owl_timer_init() failure messages (Matheus Castello)
- Add driver for the Ingenic JZ47xx OST (Maarten ter Huurne)
- Pass the interrupt and the shutdown callbacks in the init function
for ast2600 support (Joel Stanley)
- Add the ast2600 compatible string for the fttmr010 (Joel Stanley)
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQRuKdf4M92Gi9vqihve5qtOL396pgUCXnJaXQAKCRDe5qtOL396
pmVbAQChth0V/THG4aN/JySIIAmeY+u7VhYeI60AcPPpQa7iwQEA9G9ZRErogMQ/
TDqgFKiLVR6Q+pyjCM0O96Z6rqSQ4g8=
=iNoR
-----END PGP SIGNATURE-----
Merge tag 'timers-v5.7' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clockevent/clocksource updates from Daniel Lezcano:
- Avoid creating dead devices by flagging the driver with OF_POPULATED
in order to prevent the platform to create another device (Saravana Kannan)
- Remove unused includes from imx family drivers (Anson Huang)
- timer-dm-ti rework to prepare for pwm and suspend support (Lokesh Vutla)
- Fix the rate for the global clock on the pit64b (Claudiu Beznea)
- Fix timer-cs5535 by requesting an irq with non-NULL dev_id (Afzal Mohammed)
- Replace setup_irq() by request_irq() (Afzal Mohammed)
- Add support for the TCU of X1000 (Zhou Yanjie)
- Drop the bogus omap_dm_timer_of_set_source() function (Suman Anna)
- Do not update the counter when updating the period in order to
prevent a disruption when the pwm is used (Lokesh Vutla)
- Improve owl_timer_init() failure messages (Matheus Castello)
- Add driver for the Ingenic JZ47xx OST (Maarten ter Huurne)
- Pass the interrupt and the shutdown callbacks in the init function
for ast2600 support (Joel Stanley)
- Add the ast2600 compatible string for the fttmr010 (Joel Stanley)
Timer initialization is done during early boot way before the driver
core starts processing devices and drivers. Timers initialized during
this early boot period don't really need or use a struct device.
However, for timers represented as device tree nodes, the struct devices
are still created and sit around unused and wasting memory. This change
avoid this by marking the device tree nodes as "populated" if the
corresponding timer is successfully initialized.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200111052125.238212-1-saravanak@google.com
dm timer ops set_load() api allows to configure the load value and to
set the auto reload feature. But auto reload feature is independent of
load value and should be part of configuring pwm. This way pwm can be
disabled by disabling auto reload feature using set_pwm() so that the
current pwm cycle will be completed. Else pwm disabling causes the
cycle to be stopped abruptly.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200305082715.15861-7-lokeshvutla@ti.com
omap_dm_timer_ops provide support to configure the pwm but there is no
support to get the current status. For configuring pwm it is advised to
check the current hw status instead of relying on pwm framework. So
implement a new timer ops to get the current status of pwm.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Tony Lindgen <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200305082715.15861-6-lokeshvutla@ti.com
Write to trigger register(OMAP_TIMER_TRIGGER_REG) will load the value
in Load register(OMAP_TIMER_LOAD_REG) into Counter register
(OMAP_TIMER_COUNTER_REG).
omap_dm_timer_set_load() writes into trigger register every time load
register is updated. When timer is configured in pwm mode, this causes
disruption in current pwm cycle, which is not expected especially when
pwm is used as PPS signal for synchronized PTP clocks. So do not write
into trigger register on updating the period.
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200305082715.15861-5-lokeshvutla@ti.com
omap_dm_timer_enable() restores the entire context(including counter)
based on 2 conditions:
- If get_context_loss_count is populated and context is lost.
- If get_context_loss_count is not populated update unconditionally.
Case2 has a side effect of updating the counter register even though
context is not lost. When timer is configured in pwm mode, this is
causing undesired behaviour in the pwm period.
Instead of using get_context_loss_count call back, implement cpu_pm
notifier with context save and restore support. And delete the
get_context_loss_count callback all together.
Suggested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
[tony@atomide.com: removed pm_runtime calls from cpuidle calls]
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200316111453.15441-1-lokeshvutla@ti.com
Let's add runtime_suspend and resume functions and atomic enabled
flag. This way we can use these when converting to use cpuidle
for saving and restoring device context.
And we need to maintain the driver state in the driver as documented
in "9. Autosuspend, or automatically-delayed suspends" in the
Documentation/power/runtime_pm.rst document related to using driver
private lock and races with runtime_suspend().
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200305082715.15861-3-lokeshvutla@ti.com
Use SPDX-License-Identifier instead of a verbose license text.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200305082715.15861-2-lokeshvutla@ti.com
Generic clock rate needs to be set in case it was selected as timer clock
source in mchp_pit64b_init_mode(). Otherwise it will be enabled with wrong
rate.
Fixes: 625022a5f1 ("clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1584352376-32585-1-git-send-email-claudiu.beznea@microchip.com
Recently all usages of setup_irq() was replaced by request_irq().
request_irq() does a few sanity checks that were not done in
setup_irq(), if they fail irq registration will fail. One of the check
is to ensure that non-NULL dev_id is passed in the case of shared irq.
Fix it by passing non-NULL dev_id while registering the shared irq.
Fixes: cc2550b421 ("clocksource: Replace setup_irq() by request_irq()")
Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200312064817.19000-1-afzal.mohd.ma@gmail.com
The tick_periodic() function is used at the beginning part of the
bootup process for time keeping while the other clock sources are
being initialized.
The current code assumes that all the timer interrupts are handled in
a timely manner with no missing ticks. That is not actually true. Some
ticks are missed and there are some discrepancies between the tick time
(jiffies) and the timestamp reported in the kernel log. Some systems,
however, are more prone to missing ticks than the others. In the extreme
case, the discrepancy can actually cause a soft lockup message to be
printed by the watchdog kthread. For example, on a Cavium ThunderX2
Sabre arm64 system:
[ 25.496379] watchdog: BUG: soft lockup - CPU#14 stuck for 22s!
On that system, the missing ticks are especially prevalent during the
smp_init() phase of the boot process. With an instrumented kernel,
it was found that it took about 24s as reported by the timestamp for
the tick to accumulate 4s of time.
Investigation and bisection done by others seemed to point to the
commit 73f3816609 ("arm64: Advertise mitigation of Spectre-v2, or
lack thereof") as the culprit. It could also be a firmware issue as
new firmware was promised that would fix the issue.
To properly address this problem, stop assuming that there will be no
missing tick in tick_periodic(). Modify it to follow the example of
tick_do_update_jiffies64() by using another reference clock to check for
missing ticks. Since the watchdog timer uses running_clock(), it is used
here as the reference. With this applied, the soft lockup problem in the
affected arm64 system is gone and tick time tracks much more closely to the
timestamp time.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200207193929.27308-1-longman@redhat.com
do_div() does a 64-by-32 division at least on 32bit platforms, while the
divisor 'div' is explicitly casted to unsigned long, thus 64-bit on 64-bit
platforms.
The code already ensures that the divisor is less than 2^32. Hence the
proper cast type is u32.
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200130130851.29204-1-wenyang@linux.alibaba.com
While unlikely the divisor in scale64_check_overflow() could be >= 32bit in
scale64_check_overflow(). do_div() truncates the divisor to 32bit at least
on 32bit platforms.
Use div64_u64() instead to avoid the truncation to 32-bit.
[ tglx: Massaged changelog ]
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200120100523.45656-1-wenyang@linux.alibaba.com
The reasons why the extra posix_cpu_timers_exit_group() invocation has been
added are not entirely clear from the commit message. Today all that
posix_cpu_timers_exit_group() does is stop timers that are tracking the
task from firing. Every other operation on those timers is still allowed.
The practical implication of this is posix_cpu_timer_del() which could
not get the siglock after the thread group leader has exited (because
sighand == NULL) would be able to run successfully because the timer
was already dequeued.
With that locking issue fixed there is no point in disabling all of the
timers. So remove this ``tempoary'' hack.
Fixes: e0a7021710 ("posix-cpu-timers: workaround to suppress the problems with mt exec")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87o8tityzs.fsf@x220.int.ebiederm.org
posix cpu timers do not handle the death of a process well.
This is most clearly seen when a multi-threaded process calls exec from a
thread that is not the leader of the thread group. The posix cpu timer code
continues to pin the old thread group leader and is unable to find the
siglock from there.
This results in posix_cpu_timer_del being unable to delete a timer,
posix_cpu_timer_set being unable to set a timer. Further to compensate for
the problems in posix_cpu_timer_del on a multi-threaded exec all timers
that point at the multi-threaded task are stopped.
The code for the timers fundamentally needs to check if the target
process/thread is alive. This needs an extra level of indirection. This
level of indirection is already available in struct pid.
So replace cpu.task with cpu.pid to get the needed extra layer of
indirection.
In addition to handling things more cleanly this reduces the amount of
memory a timer can pin when a process exits and then is reaped from
a task_struct to the vastly smaller struct pid.
Fixes: e0a7021710 ("posix-cpu-timers: workaround to suppress the problems with mt exec")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87wo86tz6d.fsf@x220.int.ebiederm.org
The task has been already computed to take siglock before calling
arm_timer. So pass the benefit of that labor into arm_timer().
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/8736auvdt1.fsf@x220.int.ebiederm.org
As of e78c349679 ("time, signal: Protect resource use statistics
with seqlock") cpu_clock_sample_group no longers needs siglock
protection. Unfortunately no one realized it at the time.
Remove the extra locking that is for cpu_clock_sample_group and not
for cpu_clock_sample. This significantly simplifies the code.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/878skmvdts.fsf@x220.int.ebiederm.org
As of e78c349679 ("time, signal: Protect resource use statistics with
seqlock") cpu_clock_sample_group() no longer needs siglock protection so
remove the stale comment.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87eeuevduq.fsf@x220.int.ebiederm.org
request_irq() is preferred over setup_irq(). The early boot setup_irq()
invocations happen either via 'init_IRQ()' or 'time_init()', while
memory allocators are ready by 'mm_init()'.
Per tglx[1], setup_irq() existed in olden days when allocators were not
ready by the time early interrupts were initialized.
Hence replace setup_irq() by request_irq().
Seldom remove_irq() usage has been observed coupled with setup_irq(),
wherever that has been found, it too has been replaced by free_irq().
A build error that was reported by kbuild test robot <lkp@intel.com>
in the previous version of the patch also has been fixed.
[1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos
Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/91961c77c1cf93d41523f5e1ac52043f32f97077.1582799709.git.afzal.mohd.ma@gmail.com
The function omap_dm_timer_of_set_source() was originally added in
commit 31a7448f4f ("ARM: OMAP: dmtimer: Add clock source from DT"),
and is designed to set a clock source from DT using the clocks property
of a timer node. This design choice is okay for clk provider nodes but
otherwise is a bad design as typically the clocks property is used to
specify the functional clocks for a device, and not its parents.
The timer nodes now all define a timer functional clock after the
conversion to ti-sysc and the new clkctrl layout, and this results
in an attempt to set the same functional clock as its parent when a
consumer driver attempts to acquire any of these timers in the
omap_dm_timer_prepare() function. This was masked and worked around
in commit 983a5a43ec ("clocksource: timer-ti-dm: Fix pwm dmtimer
usage of fck reparenting"). Fix all of this by simply dropping the
entire function.
Any DT configuration of clock sources should be achieved using
assigned-clocks and assigned-clock-parents properties provided
by the Common Clock Framework.
Cc: Tony Lindgren <tony@atomide.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Suman Anna <s-anna@ti.com>
Tested-by: Lokesh Vutla <lokeshvutla@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200213053504.22638-1-s-anna@ti.com
Write to trigger register(OMAP_TIMER_TRIGGER_REG) will load the value
in Load register(OMAP_TIMER_LOAD_REG) into Counter register
(OMAP_TIMER_COUNTER_REG).
omap_dm_timer_set_load() writes into trigger register every time load
register is updated. When timer is configured in pwm mode, this causes
disruption in current pwm cycle, which is not expected especially when
pwm is used as PPS signal for synchronized PTP clocks. So do not write
into trigger register on updating the period.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200224050753.17784-3-lokeshvutla@ti.com
Check the return from clocksource_mmio_init, add messages in case of
an error and in case of not having a defined clock property.
Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200219004810.411190-1-matheus@castello.eng.br
OST is the OS Timer, a 64-bit timer/counter with buffered reading.
SoCs before the JZ4770 had (if any) a 32-bit OST; the JZ4770 and
JZ4780 have a 64-bit OST.
This driver will register both a clocksource and a sched_clock to the
system.
Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200212180408.30872-1-paul@crapouillou.net
The arm_arch_timer requires VDSO_CLOCKMODE_ARCHTIMER to be defined to
compile correctly. On ARM the vDSO can be disabled and when this is the
case the compilation ends prematurely with an error:
$ make ARCH=arm multi_v7_defconfig
$ ./scripts/config -d VDSO
$ make
drivers/clocksource/arm_arch_timer.c:73:44: error:
‘VDSO_CLOCKMODE_ARCHTIMER’ undeclared here (not in a function)
static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
Make the usage of VDSO_CLOCKMODE_ARCHTIMER depend on the VDSO enablement
and initialize the vdso clockmode variable with VDSO_CLOCKMODE_NONE
otherwise.
[ tglx: Match changelog and patch content. ]
Fixes: 5e3c6a312a ("ARM/arm64: vdso: Use common vdso clock mode storage")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200224151552.57274-1-vincenzo.frascino@arm.com
The ast2600 contains a fttmr010 derivative.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191107094218.13210-5-joel@jms.id.au
In preparation for supporting the ast2600, pass the shutdown and
interrupt functions to the common init callback.
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191107094218.13210-3-joel@jms.id.au
In preparation for supporting the ast2600 which uses a different method
to clear bits in the control register, use a callback for performing the
shutdown sequence.
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191107094218.13210-2-joel@jms.id.au
head is traversed using hlist_for_each_entry_rcu outside an RCU read-side
critical section but under the protection of hash_lock.
Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.
[ tglx: Removed the macro and put the condition right where it's used ]
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200216074330.GA14025@workstation-portable
When working commit 6dcd5d7a7a, a mistake was noticed by Linus:
schedule_timeout() was called without setting the task state to anything
particular.
It calls the scheduler, but doesn't delay anything, because the task stays
runnable. That happens because sched_submit_work() does nothing for tasks
in TASK_RUNNING state.
That turned out to be the intended behavior. Adding a WARN() is not useful
as the task could be woken up right after setting the state and before
reaching schedule_timeout().
Improve the comment about schedule_timeout() and describe that more
explicitly.
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200117225900.16340-1-alex.popov@linux.com
On powerpc, __arch_get_vdso_data() clobbers the link register, requiring
the caller to save it.
As the parent function already has to set a stack frame and saves the link
register before calling the C vdso function, retrieving the vdso data
pointer there is less overhead.
Split out the functional code from the __cvdso.*() interfaces into new
static functions which can either be called from the existing interfaces
with the vdso data pointer supplied via __arch_get_vdso_data() or directly
from ASM code.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/abf97996602ef07223fec30c005df78e5ed41b2e.1580399657.git.christophe.leroy@c-s.fr
Link: https://lkml.kernel.org/r/20200207124403.965789141@linutronix.de
On powerpc/32, GCC (8.1) generates pretty bad code for the ns >>= vd->shift
operation taking into account that the shift is always <= 32 and the upper
part of the result is likely to be zero. GCC makes reversed assumptions
considering the shift to be likely >= 32 and the upper part to be like not
zero.
unsigned long long shift(unsigned long long x, unsigned char s)
{
return x >> s;
}
results in:
00000018 <shift>:
18: 35 25 ff e0 addic. r9,r5,-32
1c: 41 80 00 10 blt 2c <shift+0x14>
20: 7c 64 4c 30 srw r4,r3,r9
24: 38 60 00 00 li r3,0
28: 4e 80 00 20 blr
2c: 54 69 08 3c rlwinm r9,r3,1,0,30
30: 21 45 00 1f subfic r10,r5,31
34: 7c 84 2c 30 srw r4,r4,r5
38: 7d 29 50 30 slw r9,r9,r10
3c: 7c 63 2c 30 srw r3,r3,r5
40: 7d 24 23 78 or r4,r9,r4
44: 4e 80 00 20 blr
Even when forcing the shift to be smaller than 32 with an &= 31, it still
considers the shift as likely >= 32.
Move the default shift implementation into an inline which can be redefined
in architecture code via a macro.
[ tglx: Made the shift argument u32 and removed the __arch prefix ]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/b3d449de856982ed060a71e6ace8eeca4654e685.1580399657.git.christophe.leroy@c-s.fr
Link: https://lkml.kernel.org/r/20200207124403.857649978@linutronix.de
Some architectures have a fixed clocksource which is known at compile time
and cannot be replaced or disabled at runtime, e.g. timebase on
PowerPC. For such cases the clock mode check in the VDSO code is pointless.
Move the check for a VDSO capable clocksource into an inline function and
allow architectures to redefine it via a macro.
[ tglx: Removed the #ifdef mess ]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.748756829@linutronix.de
Move the time namespace indicator clock mode to the other ones for
consistency sake.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.656097274@linutronix.de
If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.
Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de
Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de
Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de
All architectures which use the generic VDSO code have their own storage
for the VDSO clock mode. That's pointless and just requires duplicate code.
Provide generic storage for it. The new Kconfig symbol is intermediate and
will be removed once all architectures are converted over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.028046322@linutronix.de
All architectures which use the generic VDSO code have their own storage
for the VDSO clock mode. That's pointless and just requires duplicate code.
X86 abuses the function which retrieves the architecture specific clock
mode storage to mark the clocksource as used in the VDSO. That's silly
because this is invoked on every tick when the VDSO data is updated.
Move this functionality to the clocksource::enable() callback so it gets
invoked once when the clocksource is installed. This allows to make the
clock mode storage generic.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com> (Hyper-V parts)
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
Link: https://lkml.kernel.org/r/20200207124402.934519777@linutronix.de
If neither the R4K nor the GIC timer is enabled in the kernel configuration
then let the core VDSO code drop the high resolution parts at compile time.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.714585315@linutronix.de
