History log of /linux-master/drivers/clocksource/arc_timer.c
Revision Date Author Comments
# 58100c34 23-Sep-2021 Randy Dunlap <rdunlap@infradead.org>

clocksource/drivers/arc_timer: Eliminate redefined macro error

In drivers/clocksource/, 3 drivers use "TIMER_CTRL_IE" with 3 different
values. Two of them (mps2-timer.c and timer-sp804.c/timer-sp.h) are
localized and left unmodifed.

One of them uses a shared header file (<soc/arc/timers.h>), which is
what is causing the "redefined" warnings, so change the macro name in
that driver only. Also change the TIMER_CTRL_NH macro name.
Both macro names are prefixed with "ARC_" to reduce the likelihood
of future name collisions.

In file included from ../drivers/clocksource/timer-sp804.c:24:
../drivers/clocksource/timer-sp.h:25: error: "TIMER_CTRL_IE" redefined [-Werror]
25 | #define TIMER_CTRL_IE (1 << 5) /* VR */
../include/soc/arc/timers.h:20: note: this is the location of the previous definition
20 | #define TIMER_CTRL_IE (1 << 0) /* Interrupt when Count reaches limit */

Fixes: b26c2e3823ba ("ARC: breakout timer include code into separate header")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shahab Vahedi <Shahab.Vahedi@synopsys.com>
Acked-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210924020825.20317-1-rdunlap@infradead.org


# 311fb70a 29-Apr-2020 Dejin Zheng <zhengdejin5@gmail.com>

clocksource/drivers/arc_timer: Remove duplicate error message

The function arc_get_timer_clk() prints an error message if it fails,
remove the second error message if the function fails.

Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200429151223.3120-1-zhengdejin5@gmail.com


# 93665ab0 23-May-2019 Masahiro Yamada <yamada.masahiro@socionext.com>

clocksource/drivers/arc_timer: Use BIT() instead of _BITUL()

This is in-kernel C code, so there is no reason to use _BITUL().
Replace it with equivalent BIT().

I added #include <linux/bits.h> explicitly although it has been included
by other headers eventually.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>


# d2912cb1 04-Jun-2019 Thomas Gleixner <tglx@linutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

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>


# bf287607 19-Nov-2018 Alexey Brodkin <alexey.brodkin@synopsys.com>

clocksource/drivers/arc_timer: Utilize generic sched_clock

It turned out we used to use default implementation of sched_clock()
from kernel/sched/clock.c which was as precise as 1/HZ, i.e.
by default we had 10 msec granularity of time measurement.

Now given ARC built-in timers are clocked with the same frequency as
CPU cores we may get much higher precision of time tracking.

Thus we switch to generic sched_clock which really reads ARC hardware
counters.

This is especially helpful for measuring short events.
That's what we used to have:
------------------------------>8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello > /dev/null

Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

10.000000 task-clock (msec) # 2.832 CPUs utilized
1 context-switches # 0.100 K/sec
1 cpu-migrations # 0.100 K/sec
63 page-faults # 0.006 M/sec
3049480 cycles # 0.305 GHz
1091259 instructions # 0.36 insn per cycle
256828 branches # 25.683 M/sec
27026 branch-misses # 10.52% of all branches

0.003530687 seconds time elapsed

0.000000000 seconds user
0.010000000 seconds sys
------------------------------>8------------------------

And now we'll see:
------------------------------>8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello > /dev/null

Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

3.004322 task-clock (msec) # 0.865 CPUs utilized
1 context-switches # 0.333 K/sec
1 cpu-migrations # 0.333 K/sec
63 page-faults # 0.021 M/sec
2986734 cycles # 0.994 GHz
1087466 instructions # 0.36 insn per cycle
255209 branches # 84.947 M/sec
26002 branch-misses # 10.19% of all branches

0.003474829 seconds time elapsed

0.003519000 seconds user
0.000000000 seconds sys
------------------------------>8------------------------

Note how much more meaningful is the second output - time spent for
execution pretty much matches number of cycles spent (we're runnign
@ 1GHz here).

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>


# 6bd9549d 19-Apr-2018 Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>

clocksource/drivers/arc_timer: Add comments about locking while read GFRC

This came to light in some internal discussions and it is nice to have
this documented rather than digging up the PRM (Prog Ref Manual) again.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>


# a4f53857 21-Feb-2018 Vineet Gupta <Vineet.Gupta1@synopsys.com>

clocksource/drivers/arc_timer: Update some comments

TIMER0 interrupt ACK is different for ARC700 and HS3x cores.

This came to light in some internal discussions and it is nice to have this
documented rather than digging up the PRM (Programmers Reference Manual).

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Link: https://lkml.kernel.org/r/1519241491-12570-1-git-send-email-vgupta@synopsys.com


# 17273395 26-May-2017 Daniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE

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>


# ac9ce6d1 09-Mar-2017 Rafał Miłecki <rafal@milecki.pl>

clocksource: Add missing line break to error messages

Printing with pr_* functions requires adding line break manually.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>


# a5a1d1c2 21-Dec-2016 Thomas Gleixner <tglx@linutronix.de>

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>


# 73c1b41e 21-Dec-2016 Thomas Gleixner <tglx@linutronix.de>

cpu/hotplug: Cleanup state names

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>


# c4c9a040 31-Oct-2016 Vineet Gupta <vgupta@synopsys.com>

clocksource: import ARC timer driver

This adds support for

- CONFIG_ARC_TIMERS : legacy 32-bit TIMER0 and TIMER1 which count UP
from @CNT to @LIMIT, before optionally triggering an interrupt.
These are programmed using ARC auxiliary register interface.
These are present in all ARC cores (ARC700 and ARC HS38)
TIMER0 serves as clockevent for all ARC linux builds.
TIMER1 is used for clocksource in arc700 builds.

- CONFIG_ARC_TIMERS_64BIT: 64-bit counters, RTC and GFRC found in
ARC HS38 cores. These are independnet IP blocks with different
programming model respectively.

Link: http://lkml.kernel.org/r/20161111231132.GA4186@mai
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>