Commit Graph

12 Commits

Author SHA1 Message Date
Thomas Gleixner
3419240495 Merge branch 'timers/vdso' into timers/core
so the hyper-v clocksource update can be applied.
2019-07-03 10:50:21 +02:00
Masahiro Yamada
93665ab062 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>
2019-06-25 19:49:18 +02:00
Thomas Gleixner
d2912cb15b 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>
2019-06-19 17:09:55 +02:00
Alexey Brodkin
bf287607c8 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>
2018-12-18 22:22:23 +01:00
Eugeniy Paltsev
6bd9549d8a 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>
2018-05-18 22:59:40 +02:00
Vineet Gupta
a4f538573c 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
2018-02-28 13:55:14 +01:00
Daniel Lezcano
1727339590 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>
2017-06-14 11:58:45 +02:00
Rafał Miłecki
ac9ce6d1a0 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>
2017-04-07 16:23:04 +02:00
Linus Torvalds
3ddc76dfc7 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
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
2016-12-25 14:30:04 -08:00
Thomas Gleixner
a5a1d1c291 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>
2016-12-25 11:04:12 +01:00
Thomas Gleixner
73c1b41e63 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>
2016-12-25 10:47:44 +01:00
Vineet Gupta
c4c9a040ec 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>
2016-11-30 11:54:25 -08:00