The 'err' variable is initialized whatever the code path, it is
pointless to initialize it when it is declared.
Signed-off-by: Li kunyu <kunyu@nfschina.com>
Link: https://lore.kernel.org/r/20240705052159.22235-1-kunyu@nfschina.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Use GENMASK() to define the prescaler mask and make the whole driver use
the mask (together with helpers such as FIELD_{GET,PREP,FIT}) instead of
needing an additional shift and max value constant.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240225151336.2728533-4-martin.blumenstingl@googlemail.com
The result of the division of new_rate by gt_target_rate can be zero (if
new_rate is smaller than gt_target_rate). Using that result as divisor
without checking can result in a division by zero error. Guard against
this by checking for a zero value earlier.
While here, also change the psv variable to an unsigned long to make
sure we don't overflow the datatype as all other types involved are also
unsiged long.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240225151336.2728533-3-martin.blumenstingl@googlemail.com
Use a common C comment "/*" instead of a kernel-doc marker "/**"
to prevent kernel-doc warnings:
arm_global_timer.c:92: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* To ensure that updates to comparator value register do not set the
arm_global_timer.c:92: warning: missing initial short description on line:
* To ensure that updates to comparator value register do not set the
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240115053641.29129-1-rdunlap@infradead.org
The prescaler in the "Global Timer Control Register bit assignments" is
documented to use bits [15:8], which means that the maximum prescaler
register value is 0xff.
Fixes: 171b45a4a7 ("clocksource/drivers/arm_global_timer: Implement rate compensation whenever source clock changes")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240218174138.1942418-2-martin.blumenstingl@googlemail.com
Fix the following coccicheck warning:
drivers/clocksource/arm_global_timer.c:107:4-23:
duplicated argument to & or |
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210615115440.8881-1-wanjiabing@vivo.com
The sparse tool complains as follows:
drivers/clocksource/arm_global_timer.c:54:23: warning:
symbol 'gt_clk_rate_change_nb' was not declared. Should it be static?
This symbol is not used outside of arm_global_timer.c, so mark it static.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1623490046-37972-1-git-send-email-zou_wei@huawei.com
This patch adds rate change notification support for the parent clock;
should that clock change, then we try to adjust the our prescaler in order
to compensate (i.e. we adjust to still get the same timer frequency).
This is loosely based on what it's done in timer-cadence-ttc. timer-sun51,
mips-gic-timer and smp_twd.c also seem to look at their parent clock rate
and to perform some kind of adjustment whenever needed.
In this particular case we have only one single counter and prescaler for
all clocksource, clockevent and timer_delay, and we just update it for all
(i.e. we don't let it go and call clockevents_update_freq() to notify to
the kernel that our rate has changed).
Note that, there is apparently no other way to fixup things, because once
we call register_current_timer_delay(), specifying the timer rate, it seems
that that rate is not supposed to change ever.
In order for this mechanism to work, we have to make assumptions about how
much the initial clock is supposed to eventually decrease from the initial
one, and set our initial prescaler to a value that we can eventually
decrease enough to compensate. We provide an option in KConfig for this.
In case we end up in a situation in which we are not able to compensate the
parent clock change, we fail returning NOTIFY_BAD.
This fixes a real-world problem with Zynq arch not being able to use this
driver and CPU_FREQ at the same time (because ARM global timer is fed by
the CPU clock, which may keep changing when CPU_FREQ is enabled).
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210406130045.15491-2-andrea.merello@gmail.com
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the
clocksource at early stage. However, this macro is also used to initialize
the clockevent if any, or the clockevent only.
It was originally suggested to declare another macro to initialize a
clockevent, so in order to separate the two entities even they belong to the
same IP. This was not accepted because of the impact on the DT where splitting
a clocksource/clockevent definition does not make sense as it is a Linux
concept not a hardware description.
On the other side, the clocksource has not interrupt declared while the
clockevent has, so it is easy from the driver to know if the description is
for a clockevent or a clocksource, IOW it could be implemented at the driver
level.
So instead of dealing with a named clocksource macro, let's use a more generic
one: TIMER_OF_DECLARE.
The patch has not functional changes.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Pull timer type cleanups from Thomas Gleixner:
"This series does a tree wide cleanup of types related to
timers/timekeeping.
- Get rid of cycles_t and use a plain u64. The type is not really
helpful and caused more confusion than clarity
- Get rid of the ktime union. The union has become useless as we use
the scalar nanoseconds storage unconditionally now. The 32bit
timespec alike storage got removed due to the Y2038 limitations
some time ago.
That leaves the odd union access around for no reason. Clean it up.
Both changes have been done with coccinelle and a small amount of
manual mopping up"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ktime: Get rid of ktime_equal()
ktime: Cleanup ktime_set() usage
ktime: Get rid of the union
clocksource: Use a plain u64 instead of cycle_t
There is no point in having an extra type for extra confusion. u64 is
unambiguous.
Conversion was done with the following coccinelle script:
@rem@
@@
-typedef u64 cycle_t;
@fix@
typedef cycle_t;
@@
-cycle_t
+u64
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.
Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel@stlinux.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153338.062741642@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.
Let's convert back the names:
- CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
- clksrc-of-ret => clksrc-of
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
For exynos_mct and samsung_pwm_timer:
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
For arch/arc:
Acked-by: Vineet Gupta <vgupta@synopsys.com>
For mediatek driver:
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
For the Rockchip-part
Acked-by: Heiko Stuebner <heiko@sntech.de>
For STi :
Acked-by: Patrice Chotard <patrice.chotard@st.com>
For the mps2-timer.c and versatile.c changes:
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
For the OXNAS part :
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
For LPC32xx driver:
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
For Broadcom Kona timer change:
Acked-by: Ray Jui <ray.jui@broadcom.com>
For Sun4i and Sun5i:
Acked-by: Chen-Yu Tsai <wens@csie.org>
For Meson6:
Acked-by: Carlo Caione <carlo@caione.org>
For Keystone:
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
For NPS:
Acked-by: Noam Camus <noamca@mellanox.com>
For bcm2835:
Acked-by: Eric Anholt <eric@anholt.net>
The init functions do not return any error. They behave as the following:
- panic, thus leading to a kernel crash while another timer may work and
make the system boot up correctly
or
- print an error and let the caller unaware if the state of the system
Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.
Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
set_state_oneshot_stopped() is called by the clkevt core, when the next
event is required at an expiry time of 'KTIME_MAX'. This normally
happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.
This patch makes the clockevent device to stop on such an event, to
avoid spurious interrupts, as explained by: commit 8fff52fd50
("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Provide a delay timer using the lower 32-bits of the global timer so
that we can use that instead of having to calibrating delays.
Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Now the System stall is observed on TI AM437x based board (am437x-gp-evm)
during resuming from System suspend when ARM Global timer is selected as
clocksource device (CPUIdle not enabled) - SysRq are working, but nothing
else.
The reason of stall is that ARM Global timer loses its contexts during
System suspend:
GT_CONTROL.TIMER_ENABLE = 0 (unbanked)
GT_COUNTERx = 0
Hence, update ARM Global timer driver to reflect above behaviour
- re-enable ARM Global timer on resume (GT_CONTROL.TIMER_ENABLE = 1)
if not enabled.
CC: Arnd Bergmann <arnd@arndb.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Use the relaxed version to improve performance. we measured time of
4096 rounds of gt_compare_set() spent on Marvell BG2Q:
before the patch: 3690648ns on average
after the patch: 1083023ns on average
improved by 70%!
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Currently arm_global_timer can be used as a scheduler clock. We properly
marked gt_sched_clock_read() as notrace but we then call another function
gt_counter_read() that _wasn't_ notrace.
Having a traceable function in the sched_clock() path leads to a recursion
within ftrace and a kernel crash.
Fix this by adding an extra notrace function to keep other users of
gt_counter_read() traceable.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Migrate arm_global_timer driver to the new 'set-state' interface
provided by the clockevents core, the earlier 'set-mode' interface is
marked obsolete now.
This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Ensure that platform maintainers check the CPU part number in the right
manner: the CPU part number is meaningless without also checking the
CPU implement(e|o)r (choose your preferred spelling!) Provide an
interface which returns both the implementer and part number together,
and update the definitions to include the implementer.
Mark the old function as being deprecated... indeed, using the old
function with the definitions will now always evaluate as false, so
people must update their un-merged code to the new function. While
this could be avoided by adding new definitions, we'd also have to
create new names for them which would be awkward.
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The check for a usable global timer in the probe code does not enquire
which CPU we are currently running on. This can cause the driver to
incorrectly assume we have an unusable global timer if we are running
on a CPU other than A9.
Before checking the CPU revision, ensure we are running on an A9 CPU.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The 32 bit sched_clock interface now supports 64 bits. Upgrade to
the 64 bit function to allow us to remove the 32 bit registration
interface. While we're here increase the number of bits that
sched_clock can handle to 64 to make full use of the counter.
Cc: Stuart Menefy <stuart.menefy@st.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Acked-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The arm_global_timer is a per cpu device. Set the appropriate flag.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
This removes all the drivers/clocksource and drivers/irqchip uses of
the __cpuinit macros from all C files.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This is a simple driver for the global timer module found in the Cortex
A9-MP cores from revision r1p0 onwards. This should be able to perform
the functions of the system timer and the local timer in an SMP system.
The global timer has the following features:
The global timer is a 64-bit incrementing counter with an
auto-incrementing feature. It continues incrementing after sending
interrupts. The global timer is memory mapped in the private memory
region.
The global timer is accessible to all Cortex-A9 processors in the
cluster. Each Cortex-A9 processor has a private 64-bit comparator that
is used to assert a private interrupt when the global timer has reached
the comparator value. All the Cortex-A9 processors in a design use the
banked ID, ID27, for this interrupt. ID27 is sent to the Interrupt
Controller as a Private Peripheral Interrupt. The global timer is
clocked by PERIPHCLK.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Rob Herring <robherring2@gmail.com>
CC: Linus Walleij <linus.walleij@linaro.org>
CC: Will Deacon <will.deacon@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
