linux.git/drivers/clocksource/arc_timer.c, branch v6.6.132

clocksource/drivers/arc_timer: Eliminate redefined macro error

2021-10-16T20:15:01+00:00

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 (), 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 
Cc: Vineet Gupta 
Cc: linux-snps-arc@lists.infradead.org
Cc: Daniel Lezcano 
Cc: Thomas Gleixner 
Cc: Shahab Vahedi 
Acked-by: Vineet Gupta 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20210924020825.20317-1-rdunlap@infradead.org

clocksource/drivers/arc_timer: Remove duplicate error message

2020-05-22T21:58:56+00:00

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 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200429151223.3120-1-zhengdejin5@gmail.com

Merge branch 'timers/vdso' into timers/core

2019-07-03T08:50:21+00:00

so the hyper-v clocksource update can be applied.

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

2019-06-25T17:49:18+00:00

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

I added #include  explicitly although it has been included
by other headers eventually.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Daniel Lezcano

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

2019-06-19T15:09:55+00:00

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 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Kate Stewart 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/arc_timer: Utilize generic sched_clock

2018-12-18T21:22:23+00:00

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 
Cc: Daniel Lezcano 
Cc: Vineet Gupta 
Cc: Thomas Gleixner 
Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta 
Signed-off-by: Daniel Lezcano

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

2018-05-18T20:59:40+00:00

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 
Acked-by: Vineet Gupta 
Signed-off-by: Daniel Lezcano

clocksource/drivers/arc_timer: Update some comments

2018-02-28T12:55:14+00:00

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 
Signed-off-by: Thomas Gleixner 
Cc: Daniel Lezcano 
Cc: Vineet Gupta 
Cc: linux-snps-arc@lists.infradead.org
Link: https://lkml.kernel.org/r/1519241491-12570-1-git-send-email-vgupta@synopsys.com

clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE

2017-06-14T09:58:45+00:00

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 
Acked-by: Heiko Stuebner 
Acked-by: Neil Armstrong 
Acked-by: Arnd Bergmann 
Acked-by: Matthias Brugger 
Reviewed-by: Linus Walleij

clocksource: Add missing line break to error messages

2017-04-07T14:23:04+00:00

Printing with pr_* functions requires adding line break manually.

Signed-off-by: Rafał Miłecki 
Acked-by: Thierry Reding 
Signed-off-by: Daniel Lezcano