The CSR SiRF prima2/atlas platforms are getting removed, so this driver
is no longer needed.
Cc: Barry Song <baohua@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210120131559.1971359-5-arnd@kernel.org
The CSR SiRF prima2/atlas platforms are getting removed, so this driver
is no longer needed.
Cc: Barry Song <baohua@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210120131559.1971359-4-arnd@kernel.org
The tango platform is getting removed, so the driver is no
longer needed.
Cc: Marc Gonzalez <marc.w.gonzalez@free.fr>
Cc: Mans Rullgard <mans@mansr.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210120131559.1971359-3-arnd@kernel.org
The ST-Ericsson U300 platform is getting removed, so this driver is no
longer needed.
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210120131559.1971359-2-arnd@kernel.org
The NPCM750 Timer/Watchdog Controller has multiple interrupt lines,
connected to multiple timers. The driver uses timer 0 for timer
interrupts, so the interrupt line corresponding to timer 0 should be
specified in DT.
I removed the mention of "flags for falling edge", because the timer
controller uses high-level interrupts rather than falling-edge
interrupts, and whether flags should be specified is up the interrupt
controller's DT binding.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210108163004.492649-1-j.neuschaefer@gmx.net
We no longer need to undef pr_fmt if we define our own before including
any headers.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210111140814.3668-1-brgl@bgdev.pl
In the !CONFIG_GENERIC_CMOS_UPDATE case the update_persistent_clock64() function
gets defined as a stub in ntp.c - make the prototype in <linux/timekeeping.h>
conditional on CONFIG_GENERIC_CMOS_UPDATE as well.
Fixes: 76e87d96b3 ("ntp: Consolidate the RTC update implementation")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
- Fix overhead for erratum handling when the timer has no erratum and
fix fault programing for the event stream on the arm arch timer
(Keqian Zhu)
- Fix potential deadlock when calling runtime PM on sh_cmt (Niklas
Söderlund)
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEGn3N4YVz0WNVyHskqDIjiipP6E8FAl/SBCgACgkQqDIjiipP
6E+ypgf/XwlisP+5jTWMlvkbbC4HvFoXzB8DBhkDeCA7zaMDRvshIjKu77NQgBo5
pKEwPKwnZiMDp2CgLFT2fLFsjzS4piVS6fw+xNdkDPdfQ+qzIsdT52gpRpAXHnBK
A97bZx2k4GieaJQDh5vMaQuy2VxxN8Xclh/iyv9ILc7nLgBa4th88JXhtH/9Ibee
pBixSpNgzr+J/7EufHgBecZ6Jd/yyWgQQfJYygflg4N8QFiqN6pQvVod9yOfqayD
9deu53pnjddahpGuE0s0L4ZXpG8/U3JQg52rVW9BgG4WgFjBimWGmQFXHmXhEBzD
tQsRpVCnF6Iv8RHNhXC9DVNaBGHiVg==
=/RLp
-----END PGP SIGNATURE-----
Merge tag 'timers-v5.11-2' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clocksource/events updates from Daniel Lezcano:
- Fix error handling if no clock is available on dw_apb_timer_of (Dinh Nguyen)
- Fix overhead for erratum handling when the timer has no erratum and
fix fault programing for the event stream on the arm arch timer
(Keqian Zhu)
- Fix potential deadlock when calling runtime PM on sh_cmt (Niklas
Söderlund)
The quick check in tick_do_update_jiffies64() whether jiffies need to be
updated is not really correct under all circumstances and on all
architectures, especially not on 32bit systems.
The quick check does:
if (now < READ_ONCE(tick_next_period))
return;
and the counterpart in the update is:
WRITE_ONCE(tick_next_period, next_update_time);
This has two problems:
1) On weakly ordered architectures there is no guarantee that the stores
before the WRITE_ONCE() are visible which means that other CPUs can
operate on a stale jiffies value.
2) On 32bit the store of tick_next_period which is an u64 is split into
two 32bit stores. If the first 32bit store advances tick_next_period
far out and the second 32bit store is delayed (virt, NMI ...) then
jiffies will become stale until the second 32bit store happens.
Address this by seperating the handling for 32bit and 64bit.
On 64bit problem #1 is addressed by replacing READ_ONCE() / WRITE_ONCE()
with smp_load_acquire() / smp_store_release().
On 32bit problem #2 is addressed by protecting the quick check with the
jiffies sequence counter. The load and stores can be plain because the
sequence count mechanics provides the required barriers already.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/87czzpc02w.fsf@nanos.tec.linutronix.de
The code for the legacy RTC and the RTC class based update are pretty much
the same. Consolidate the common parts into one function and just invoke
the actual setter functions.
For RTC class based devices the update code checks whether the offset is
valid for the device, which is usually not the case for the first
invocation. If it's not the same it stores the correct offset and lets the
caller try again. That's not much different from the previous approach
where the first invocation had a pretty low probability to actually hit the
allowed window.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.355743355@linutronix.de
The current RTC set_offset_nsec value is not really intuitive to
understand.
tsched twrite(t2.tv_sec - 1) t2 (seconds increment)
The offset is calculated from twrite based on the assumption that t2 -
twrite == 1s. That means for the MC146818 RTC the offset needs to be
negative so that the write happens 500ms before t2.
It's easier to understand when the whole calculation is based on t2. That
avoids negative offsets and the meaning is obvious:
t2 - twrite: The time defined by the chip when seconds increment
after the write.
twrite - tsched: The time for the transport to the point where the chip
is updated.
==> set_offset_nsec = t2 - tsched
ttransport = twrite - tsched
tRTCinc = t2 - twrite
==> set_offset_nsec = ttransport + tRTCinc
tRTCinc is a chip property and can be obtained from the data sheet.
ttransport depends on how the RTC is connected. It is close to 0 for
directly accessible RTCs. For RTCs behind a slow bus, e.g. i2c, it's the
time required to send the update over the bus. This can be estimated or
even calibrated, but that's a different problem.
Adjust the implementation and update comments accordingly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.263204937@linutronix.de
rtc_set_ntp_time() is not really RTC functionality as the code is just a
user of RTC. Move it into the NTP code which allows further cleanups.
Requested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.166871172@linutronix.de
Miroslav reported that the periodic RTC synchronization in the NTP code
fails more often than not to hit the specified update window.
The reason is that the code uses delayed_work to schedule the update which
needs to be in thread context as the underlying RTC might be connected via
a slow bus, e.g. I2C. In the update function it verifies whether the
current time is correct vs. the requirements of the underlying RTC.
But delayed_work is using the timer wheel for scheduling which is
inaccurate by design. Depending on the distance to the expiry the wheel
gets less granular to allow batching and to avoid the cascading of the
original timer wheel. See 500462a9de ("timers: Switch to a non-cascading
wheel") and the code for further details.
The code already deals with this by splitting the 660 seconds period into a
long 659 seconds timer and then retrying with a smaller delta.
But looking at the actual granularities of the timer wheel (which depend on
the HZ configuration) the 659 seconds timer ends up in an outer wheel level
and is affected by a worst case granularity of:
HZ Granularity
1000 32s
250 16s
100 40s
So the initial timer can be already off by max 12.5% which is not a big
issue as the period of the sync is defined as ~11 minutes.
The fine grained second attempt schedules to the desired update point with
a timer expiring less than a second from now. Depending on the actual delta
and the HZ setting even the second attempt can end up in outer wheel levels
which have a large enough granularity to make the correctness check fail.
As this is a fundamental property of the timer wheel there is no way to
make this more accurate short of iterating in one jiffies steps towards the
update point.
Switch it to an hrtimer instead which schedules the actual update work. The
hrtimer will expire precisely (max 1 jiffie delay when high resolution
timers are not available). The actual scheduling delay of the work is the
same as before.
The update is triggered from do_adjtimex() which is a bit racy but not much
more racy than it was before:
if (ntp_synced())
queue_delayed_work(system_power_efficient_wq, &sync_work, 0);
which is racy when the work is currently executed and has not managed to
reschedule itself.
This becomes now:
if (ntp_synced() && !hrtimer_is_queued(&sync_hrtimer))
queue_work(system_power_efficient_wq, &sync_work, 0);
which is racy when the hrtimer has expired and the work is currently
executed and has not yet managed to rearm the hrtimer.
Not a big problem as it just schedules work for nothing.
The new implementation has a safe guard in place to catch the case where
the hrtimer is queued on entry to the work function and avoids an extra
update attempt of the RTC that way.
Reported-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Miroslav Lichvar <mlichvar@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.062910520@linutronix.de
The offset which is used to steer the start of an RTC synchronization
update via rtc_set_ntp_time() is huge. The math behind this is:
tsched twrite(t2.tv_sec - 1) t2 (seconds increment)
twrite - tsched is the transport time for the write to hit the device.
t2 - twrite depends on the chip and is for most chips one second.
The rtc_set_ntp_time() calculation of tsched is:
tsched = t2 - 1sec - (t2 - twrite)
The default for the sync offset is 500ms which means that twrite - tsched
is 500ms assumed that t2 - twrite is one second.
This is 0.5 seconds off for RTCs which are directly accessible by IO writes
and probably for the majority of i2C/SPI based RTC off by an order of
magnitude. Set it to 5ms which should bring it closer to reality.
The default can be adjusted by drivers (rtc_cmos does so) and could be
adjusted further by a calibration method which is an orthogonal problem.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.960333166@linutronix.de
The offset for rtc_cmos must be -500ms to work correctly with the current
implementation of rtc_set_ntp_time() due to the following:
tsched twrite(t2.tv_sec - 1) t2 (seconds increment)
twrite - tsched is the transport time for the write to hit the device,
which is negligible for this chip because it's accessed directly.
t2 - twrite = 500ms according to the datasheet.
But rtc_set_ntp_time() calculation of tsched is:
tsched = t2 - 1sec - (t2 - twrite)
The default for the sync offset is 500ms which means that the write happens
at t2 - 1.5 seconds which is obviously off by a second for this device.
Make the offset -500ms so it works correct.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.830517160@linutronix.de
The MC146818 driver is prone to read garbage from the RTC. There are
several issues all related to the update cycle of the MC146818. The chip
increments seconds obviously once per second and indicates that by a bit in
a register. The bit goes high 244us before the actual update starts. During
the update the readout of the time values is undefined.
The code just checks whether the update in progress bit (UIP) is set before
reading the clock. If it's set it waits arbitrary 20ms before retrying,
which is ample because the maximum update time is ~2ms.
But this check does not guarantee that the UIP bit goes high and the actual
update happens during the readout. So the following can happen
0.997 UIP = False
-> Interrupt/NMI/preemption
0.998 UIP -> True
0.999 Readout <- Undefined
To prevent this rework the code so it checks UIP before and after the
readout and if set after the readout try again.
But that's not enough to cover the following:
0.997 UIP = False
Readout seconds
-> NMI (or vCPU scheduled out)
0.998 UIP -> True
update completes
UIP -> False
1.000 Readout minutes,....
UIP check succeeds
That can make the readout wrong up to 59 seconds.
To prevent this, read the seconds value before the first UIP check,
validate it after checking UIP and after reading out the rest.
It's amazing that the original i386 code had this actually correct and
the generic implementation of the MC146818 driver got it wrong in 2002 and
it stayed that way until today.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.594826678@linutronix.de
ARM virtual counter supports event stream, it can only trigger an event
when the trigger bit (the value of CNTKCTL_EL1.EVNTI) of CNTVCT_EL0 changes,
so the actual period of event stream is 2^(cntkctl_evnti + 1). For example,
when the trigger bit is 0, then virtual counter trigger an event for every
two cycles.
While we're at it, rework the way we compute the trigger bit position
by making it more obvious that when bits [n:n-1] are both set (with n
being the most significant bit), we pick bit (n + 1).
Fixes: 037f637767 ("drivers: clocksource: add support for ARM architected timer event stream")
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201204073126.6920-3-zhukeqian1@huawei.com
In commit 0ea415390c ("clocksource/arm_arch_timer: Use arch_timer_read_counter
to access stable counters"), we separate stable and normal count reader to omit
unnecessary overhead on systems that have no timer erratum.
However, in erratum_set_next_event_tval_generic(), count reader becomes normal
reader. This converts it to stable reader.
Fixes: 0ea415390c ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters")
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201204073126.6920-2-zhukeqian1@huawei.com
commit ("b0fc70ce1f02 arm64: berlin: Select DW_APB_TIMER_OF") added the
support for the dw_apb_timer into the arm64 defconfig. However, for some
platforms like the Intel Stratix10 and Agilex, the clock manager doesn't
get loaded until after the timer driver get loaded. Thus, the driver hits
the panic "No clock nor clock-frequency property for" because it cannot
properly get the clock.
This patch adds the error handling needed for the timer driver so that
the kernel can continue booting instead of just hitting the panic.
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201205105223.208604-1-dinguyen@kernel.org
- Code cleanups and error code path at init time fixes on the sp804
(Kefen Wang)
- Add new OST timer driver device tree bindings (Zhou Yanjie)
- Remove EZChip NPS clocksource driver corresponding to the NPS
platform which was removed from the ARC architecture (Vineet Gupta)
- Add missing clk_disable_unprepare() on error path for Orion (Yang
Yingliang)
- Add device tree bindings documentation for Renesas r8a774e1
(Marian-Cristian Rotariu)
- Convert Renesas TMU to json-schema (Geert Uytterhoeven)
- Fix memory leak on the error path at init time on the cadence_ttc
driver (Yu Kuai)
- Fix section mismatch for Ingenic timer driver (Daniel Lezcano)
- Make RISCV_TIMER depends on RISCV_SBI (Kefeng Wang)
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEGn3N4YVz0WNVyHskqDIjiipP6E8FAl/JOi0ACgkQqDIjiipP
6E+tWQf+J+z4jPuzEgcGHk+SzaR9rwTpz8+kEmHBFefDVVEIdarAtgtNqOLsdkwM
uLvbNI7KX2wrXEXH1tK2SYTOO0iRHKAchROucA0CxTUdOoCFguGEXjimlq0EzZ9N
xq3uAd2joJ7HZKhVrKXaB2tPa/QuuX+T0GOLmzKWNN44fD+tIGCsLmu1+/vgypu1
4OTnHb+ps+O99ZqZnpNM8sDd0zJ4dTQj1ptNtys8yhs5nBDXOXHGknLYxFyd0oZP
p5DlIUZsD3OfY2qRnh1rPhTU61IW0R3V2nq3PfJy3h5DZm/5+XkL4CTG51Ef01UX
N+EAiyW1pnfStDiaa0UIu6JKzIsbuA==
=hVIS
-----END PGP SIGNATURE-----
Merge tag 'timers-v5.11' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clocksource/event driver updates from Daniel Lezcano:
- Add static annotation for the sp804 init functions (Zhen Lei)
- Code cleanups and error code path at init time fixes on the sp804
(Kefen Wang)
- Add new OST timer driver device tree bindings (Zhou Yanjie)
- Remove EZChip NPS clocksource driver corresponding to the NPS
platform which was removed from the ARC architecture (Vineet Gupta)
- Add missing clk_disable_unprepare() on error path for Orion (Yang
Yingliang)
- Add device tree bindings documentation for Renesas r8a774e1
(Marian-Cristian Rotariu)
- Convert Renesas TMU to json-schema (Geert Uytterhoeven)
- Fix memory leak on the error path at init time on the cadence_ttc
driver (Yu Kuai)
- Fix section mismatch for Ingenic timer driver (Daniel Lezcano)
- Make RISCV_TIMER depends on RISCV_SBI (Kefeng Wang)
Link: https://lore.kernel.org/r/028084fa-d29b-a1d5-7eab-17f77ef69863@linaro.org
The riscv timer is set via SBI timer call, let's make RISCV_TIMER
depends on RISCV_SBI, and it also fixes some build issue.
Fixes: d5be89a8d1 ("RISC-V: Resurrect the MMIO timer implementation for M-mode systems")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201028131230.72907-1-wangkefeng.wang@huawei.com
The function ingenic_tcu_get_clock() is annotated for the __init
section but it is actually called from the online cpu callback.
That will lead to a crash if a CPU is hotplugged after boot time.
Remove the __init annotation for the ingenic_tcu_get_clock()
function.
Fixes: f19d838d08 (clocksource/drivers/ingenic: Add high resolution timer support for SMP/SMT)
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Link: https://lore.kernel.org/r/20201125102346.1816310-1-daniel.lezcano@linaro.org
If clk_notifier_register() failed, ttc_setup_clockevent() will return
without freeing 'ttcce', which will leak memory.
Fixes: 70504f311d ("clocksource/drivers/cadence_ttc: Convert init function to return error")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201116135123.2164033-1-yukuai3@huawei.com
Convert the Renesas R-Mobile/R-Car Timer Unit (TMU) Device Tree binding
documentation to json-schema.
Document missing properties.
Update the example to match reality.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20201110162014.3290109-3-geert+renesas@glider.be
After calling clk_prepare_enable(), clk_disable_unprepare() need
be called on error path.
Fixes: fbe4b3566d ("clocksource/drivers/orion: Convert init function...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201111064706.3397156-1-yangyingliang@huawei.com
NPS platform has been removed from ARC port and there are no in-tree
users of it now. So RIP !
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201105212210.1891598-2-vgupta@synopsys.com
The new OST has one global timer and two or four percpu timers, so there
will be three combinations in the upcoming new OST driver: the original
GLOBAL_TIMER + PERCPU_TIMER, the new GLOBAL_TIMER + PERCPU_TIMER0/1 and
GLOBAL_TIMER + PERCPU_TIMER0/1/2/3, For this, add the macro definition
about OST_CLK_PERCPU_TIMER0/1/2/3. And in order to ensure that all the
combinations work normally, the original ABI values of OST_CLK_PERCPU_TIMER
and OST_CLK_GLOBAL_TIMER need to be exchanged to ensure that in any
combinations, the clock can be registered (by calling clk_hw_register())
from index 0.
Before this patch, OST_CLK_PERCPU_TIMER and OST_CLK_GLOBAL_TIMER are only
used in two places, one is when using "assigned-clocks" to configure the
clocks in the DTS file; the other is when registering the clocks in the
sysost driver. When the values of these two ABIs are exchanged, the ABI
value used by sysost driver when registering the clock, and the ABI value
used by DTS when configuring the clock using "assigned-clocks" will also
change accordingly. Therefore, there is no situation that causes the wrong
clock to the configured. Therefore, exchanging ABI values will not cause
errors in the existing codes when registering and configuring the clocks.
Currently, in the mainline, only X1000 and X1830 are using sysost driver,
and the upcoming X2000 will also use sysost driver. This patch has been
tested on all three SoCs and all works fine.
Tested-by: 周正 (Zhou Zheng) <sernia.zhou@foxmail.com>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201026155842.10196-2-zhouyanjie@wanyeetech.com
drivers/clocksource/timer-sp804.c:38:31: warning: symbol 'arm_sp804_timer' was not declared. Should it be static?
drivers/clocksource/timer-sp804.c:47:31: warning: symbol 'hisi_sp804_timer' was not declared. Should it be static?
drivers/clocksource/timer-sp804.c:120:12: warning: symbol 'sp804_clocksource_and_sched_clock_init' was not declared. Should it be static?
drivers/clocksource/timer-sp804.c:219:12: warning: symbol 'sp804_clockevents_init' was not declared. Should it be static?
And move __initdata after the variables.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201029123317.90286-2-wangkefeng.wang@huawei.com
Add static for sp804_clocksource_and_sched_clock_init() and
sp804_clockevents_init(), they are only used in timer-sp804.c now.
Otherwise, the following warning will be reported:
drivers/clocksource/timer-sp804.c:68:12: warning: no previous prototype \
for 'sp804_clocksource_and_sched_clock_init' [-Wmissing-prototypes]
drivers/clocksource/timer-sp804.c:162:12: warning: no previous prototype \
for 'sp804_clockevents_init' [-Wmissing-prototypes]
Fixes: 975434f8b2 ("clocksource/drivers/sp804: Delete the leading "__" of some functions")
Fixes: 65f4d7ddc7 ("clocksource/drivers/sp804: Remove unused sp804_timer_disable() and timer-sp804.h")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201021012259.2067-2-thunder.leizhen@huawei.com
The variable tick_period is initialized to NSEC_PER_TICK / HZ during boot
and never updated again.
If NSEC_PER_TICK is not an integer multiple of HZ this computation is less
accurate than TICK_NSEC which has proper rounding in place.
Aside of the inaccuracy there is no reason for having this variable at
all. It's just a pointless indirection and all usage sites can just use the
TICK_NSEC constant.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.766643526@linutronix.de
calc_load_global() does not need the sequence count protection.
[ tglx: Split it up properly and added comments ]
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.660902274@linutronix.de
If jiffies are up to date already (caller lost the race against another
CPU) there is no point to change the sequence count. Doing that just forces
other CPUs into the seqcount retry loop in tick_nohz_next_event() for
nothing.
Just bail out early.
[ tglx: Rewrote most of it ]
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.462195901@linutronix.de
No point in doing calculations.
tick_next_period = last_jiffies_update + tick_period
Just check whether now is before tick_next_period to figure out whether
jiffies need an update.
Add a comment why the intentional data race in the quick check is safe or
not so safe in a 32bit corner case and why we don't worry about it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.337366695@linutronix.de
tick_broadcast_setup_oneshot() accesses tick_next_period twice without any
serialization. This is wrong in two aspects:
- Reading it twice might make the broadcast data inconsistent if the
variable is updated concurrently.
- On 32bit systems the access might see an partial update
Protect it with jiffies_lock. That's safe as none of the callchains leading
up to this function can create a lock ordering violation:
timer interrupt
run_local_timers()
hrtimer_run_queues()
hrtimer_switch_to_hres()
tick_init_highres()
tick_switch_to_oneshot()
tick_broadcast_switch_to_oneshot()
or
tick_check_oneshot_change()
tick_nohz_switch_to_nohz()
tick_switch_to_oneshot()
tick_broadcast_switch_to_oneshot()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.061341507@linutronix.de
The hrtimer_get_remaining() markup is documenting, instead,
__hrtimer_get_remaining(), as it is placed at the C file.
In order to properly document it, a kernel-doc markup is needed together
with the function prototype. So, add a new one, while preserving the
existing one, just fixing the function name.
The hrtimer_is_queued prototype has a typo: it is using
'=' instead of '-' to split: identifier - description
as required by kernel-doc markup.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/9dc87808c2fd07b7e050bafcd033c5ef05808fea.1605521731.git.mchehab+huawei@kernel.org
No users outside of the timer code. Move the caller below this function to
avoid a pointless forward declaration.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The kernel-doc parser complains:
kernel/time/timekeeping.c:1543: warning: Function parameter or member
'ts' not described in 'read_persistent_clock64'
kernel/time/timekeeping.c:764: warning: Function parameter or member
'tk' not described in 'timekeeping_forward_now'
kernel/time/timekeeping.c:1331: warning: Function parameter or member
'ts' not described in 'timekeeping_inject_offset'
kernel/time/timekeeping.c:1331: warning: Excess function parameter 'tv'
description in 'timekeeping_inject_offset'
Add the missing parameter documentations and rename the 'tv' parameter of
timekeeping_inject_offset() to 'ts' so it matches the implemention.
[ tglx: Reworded a few docs and massaged changelog ]
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-5-git-send-email-alex.shi@linux.alibaba.com
Address the following kernel-doc markup warnings:
kernel/time/timekeeping.c:1563: warning: Function parameter or member
'wall_time' not described in 'read_persistent_wall_and_boot_offset'
kernel/time/timekeeping.c:1563: warning: Function parameter or member
'boot_offset' not described in 'read_persistent_wall_and_boot_offset'
The parameters are described but miss the leading '@' and the colon after
the parameter names.
[ tglx: Massaged changelog ]
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-6-git-send-email-alex.shi@linux.alibaba.com
The kernel-doc parser complains about:
kernel/time/timekeeping.c:651: warning: Function parameter or member
'nb' not described in 'pvclock_gtod_register_notifier'
kernel/time/timekeeping.c:670: warning: Function parameter or member
'nb' not described in 'pvclock_gtod_unregister_notifier'
Add the missing parameter explanations.
[ tglx: Massaged changelog ]
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-3-git-send-email-alex.shi@linux.alibaba.com
Alex reported the following warning:
kernel/time/timekeeping.c:464: warning: Function parameter or member
'tkf' not described in '__ktime_get_fast_ns'
which is not entirely correct because the documented function is
ktime_get_mono_fast_ns() which does not have a parameter, but the
kernel-doc parser looks at the function declaration which follows the
comment and complains about the missing parameter documentation.
Aside of that the documentation for the rest of the NMI safe accessors is
either incomplete or missing.
- Move the function documentation to the right place
- Fixup the references and inconsistencies
- Add the missing documentation for ktime_get_raw_fast_ns()
Reported-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Address the following warning:
kernel/time/timekeeping.c:415: warning: Function parameter or member
'tkf' not described in 'update_fast_timekeeper'
[ tglx: Remove the bogus ktime_get_mono_fast_ns() part ]
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-2-git-send-email-alex.shi@linux.alibaba.com
