Commit graph

20 commits

Author SHA1 Message Date
Serge Semin
cee43dbf2e clocksource: dw_apb_timer: Make CPU-affiliation being optional
Currently the DW APB Timer driver binds each clockevent timers to a
particular CPU. This isn't good for multiple reasons. First of all seeing
the device is placed on APB bus (which makes it accessible from any CPU
core), accessible over MMIO and having the DYNIRQ flag set we can be sure
that manually binding the timer to any CPU just isn't correct. By doing
so we just set an extra limitation on device usage. This also doesn't
reflect the device actual capability, since by setting the IRQ affinity
we can make it virtually local to any CPU. Secondly imagine if you had a
real CPU-local timer with the same rating and the same CPU-affinity.
In this case if DW APB timer was registered first, then due to the
clockevent framework tick-timer selection procedure we'll end up with the
real CPU-local timer being left unselected for clock-events tracking. But
on most of the platforms (MIPS/ARM/etc) such timers are normally embedded
into the CPU core and are accessible with much better performance then
devices placed on APB. For instance in MIPS architectures there is
r4k-timer, which is CPU-local, assigned with the same rating, and normally
its clockevent device is registered after the platform-specific one.

So in order to fix all of these issues let's make the DW APB Timer CPU
affinity being optional and deactivated by passing a negative CPU id,
which will effectively set the DW APB clockevent timer cpumask to
'cpu_possible_mask'.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200521204818.25436-5-Sergey.Semin@baikalelectronics.ru
2020-05-23 00:02:41 +02:00
afzal mohammed
cc2550b421 clocksource: Replace setup_irq() by request_irq()
request_irq() is preferred over setup_irq(). The early boot setup_irq()
invocations happen either via 'init_IRQ()' or 'time_init()', while
memory allocators are ready by 'mm_init()'.

Per tglx[1], setup_irq() existed in olden days when allocators were not
ready by the time early interrupts were initialized.

Hence replace setup_irq() by request_irq().

Seldom remove_irq() usage has been observed coupled with setup_irq(),
wherever that has been found, it too has been replaced by free_irq().

A build error that was reported by kbuild test robot <lkp@intel.com>
in the previous version of the patch also has been fixed.

[1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos

Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/91961c77c1cf93d41523f5e1ac52043f32f97077.1582799709.git.afzal.mohd.ma@gmail.com
2020-02-27 12:15:24 +01:00
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
Thomas Gleixner
821596a50a Merge branch 'clockevents/4.12' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clockevents updates from Daniel Lezcano

- Provide a framework to handle errata gracefuly for arm_arch_timer (Mark
   Zyngier)

 - Clarify the DT properties for the rockchip timer and add the clocksource as
   an alternative to the bogus architected timer (Alexander Kochetkov)

 - Rename the Gemini timer to Faraday timer fttmr010 and provide a specific
   initialization for Gemini (Linus Walleij)

 - Add missing newlines in the error message in the timers (Rafał Miłecki)

 - Read the clock once and implement the delay timer on Orion (Russell King)
2017-04-17 10:55:14 +02:00
Nicolai Stange
8317b53fbe clockevents/drivers/dw_apb: Set ->min_delta_ticks and ->max_delta_ticks
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.

Make the dw_apb clockevent driver initialize these fields properly.

This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-04-14 13:11:13 -07:00
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
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
Jisheng Zhang
457353260d clockevents/drivers/dw_apb_timer: Implement ->set_state_oneshot_stopped()
The dw_apb_timer only "supports PERIODIC mode and their drivers emulate
ONESHOT over that" as described in commit 8fff52fd50 ("clockevents:
Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").

Inspired by Viresh, I think the dw_apb_timer also needs to implement
the set_state_oneshot_stopped() which 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 the above commit.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-04-28 15:09:03 +02:00
Jisheng Zhang
520ddad4e5 clocksource/drivers/dw_apb_timer: Inline apbt_readl and apbt_writel
It seems gcc can automatically inline apbt_writel() for us, but
apbt_real isn't inlined. This patch makes them inline to get a trivial
performance improvement: 4096 rounds of __apbt_read_clocksource() call
spend time on Marvell BG4CT platform:

 before the patch 1275240ns on average
 after the patch 1263240ns on average

so we get 1% performance improvement.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-12-15 21:41:28 +01:00
Jisheng Zhang
39d3611f2d clocksource/drivers/dw_apb_timer: Use {readl|writel}_relaxed in critical path
It's safe to use the relaxed version. From another side, the relaxed io
accessor macros are available on all architectures now, so we can use
the relaxed versions to get a trivial system performance improvement,
we measured time the following functions spent on Marvell BG4CT:

4096 rounds of __apbt_read_clocksource() call:

before the patch: 1263240ns on average
after the patch: 1250080ns on average
improved by 1%

4096 rounds of apbt_eoi() call:

before the patch: 1290960ns on average
after the patch: 1248240ns on average

4096 rounds of apbt_next_event() call:

before the patch: 3333660ns on average
after the patch: 1322040ns on average

improved by 60%!

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-12-15 21:41:28 +01:00
Jisheng Zhang
9f4165dc4e clocksource/drivers/dw_apb_timer: Fix apbt_readl return types
On Marvell BG4CT platform, we observed the __apbt_read_clocksource()
return wrong value: Let's assume the APBTMR_N_CURRENT_VALUE value is
0xf0000000, we got 0xffffffff0fffffff, but it should be 0xfffffff.

This issue should be common on all 64bit platforms. We fix the issue
by letting aptb_readl() return u32. apbt_writel() is also updated
to write u32 val rather than unsigned long.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-12-15 20:44:54 +01:00
Jisheng Zhang
8b5f0010fe clockevents/drivers/dw_apb_timer: Add dynamic irq flag to the timer
Commit d2348fb6fd ("tick: Dynamically set broadcast irq affinity")
adds one excellent feature CLOCK_EVT_FEAT_DYNIRQ to let the core set the
interrupt affinity of the broadcast interrupt to the cpu which has the
earliest expiry time. This patch adds CLOCK_EVT_FEAT_DYNIRQ flag to
avoid unnecessary wakeups and IPIs when the dw_apb_timer is used as
broadcast timer.

A simple test:
~ # rm /tmp/test.sh
~ # cat > /tmp/test.sh
cat /proc/interrupts
for i in `seq 10` ; do sleep $i; done
cat /proc/interrupts
~ # chmod +x /tmp/test.sh
~ # taskset 0x2 /tmp/test.sh

without the patch:

           CPU0       CPU1
 27:        115         36       GIC  27  arch_timer
 45:         62          0       GIC  45  mmc0
160:         88          0  interrupt-controller   8  timer
227:          0          0  interrupt-controller   4  f7e81400.i2c
228:          0          0  interrupt-controller   5  f7e81800.i2c
229:          0          0  interrupt-controller   7  dw_spi65535
230:          0          0  interrupt-controller  21  f7e84000.i2c
231:          0          0  interrupt-controller  20  f7e84800.i2c
265:        445          0  interrupt-controller   8  serial
IPI0:          0          0  CPU wakeup interrupts
IPI1:          0         11  Timer broadcast interrupts
IPI2:         56        104  Rescheduling interrupts
IPI3:          0          0  Function call interrupts
IPI4:          0          4  Single function call interrupts
IPI5:          0          0  CPU stop interrupts
IPI6:         25         27  IRQ work interrupts
IPI7:          0          0  completion interrupts
IPI8:          0          0  CPU backtrace
Err:          0
           CPU0       CPU1
 27:        115         38       GIC  27  arch_timer
 45:         62          0       GIC  45  mmc0
160:        160          0  interrupt-controller   8  timer
227:          0          0  interrupt-controller   4  f7e81400.i2c
228:          0          0  interrupt-controller   5  f7e81800.i2c
229:          0          0  interrupt-controller   7  dw_spi65535
230:          0          0  interrupt-controller  21  f7e84000.i2c
231:          0          0  interrupt-controller  20  f7e84800.i2c
265:        514          0  interrupt-controller   8  serial
IPI0:          0          0  CPU wakeup interrupts
IPI1:          0         83  Timer broadcast interrupts
IPI2:         56        104  Rescheduling interrupts
IPI3:          0          0  Function call interrupts
IPI4:          0          4  Single function call interrupts
IPI5:          0          0  CPU stop interrupts
IPI6:         25         46  IRQ work interrupts
IPI7:          0          0  completion interrupts
IPI8:          0          0  CPU backtrace
Err:          0

cpu0 get 160-88=72 timer interrupts, CPU1 got 83-11=72 broadcast timer
IPIs
So, overall system got 72+72=144 wake ups and 72 broadcast timer IPIs

With the patch:
           CPU0       CPU1
 27:        107         37       GIC  27  arch_timer
 45:         62          0       GIC  45  mmc0
160:         66          7  interrupt-controller   8  timer
227:          0          0  interrupt-controller   4  f7e81400.i2c
228:          0          0  interrupt-controller   5  f7e81800.i2c
229:          0          0  interrupt-controller   7  dw_spi65535
230:          0          0  interrupt-controller  21  f7e84000.i2c
231:          0          0  interrupt-controller  20  f7e84800.i2c
265:        311          0  interrupt-controller   8  serial
IPI0:          0          0  CPU wakeup interrupts
IPI1:          2          4  Timer broadcast interrupts
IPI2:         58        100  Rescheduling interrupts
IPI3:          0          0  Function call interrupts
IPI4:          0          4  Single function call interrupts
IPI5:          0          0  CPU stop interrupts
IPI6:         21         24  IRQ work interrupts
IPI7:          0          0  completion interrupts
IPI8:          0          0  CPU backtrace
Err:          0
           CPU0       CPU1
 27:        107         39       GIC  27  arch_timer
 45:         62          0       GIC  45  mmc0
160:         69         75  interrupt-controller   8  timer
227:          0          0  interrupt-controller   4  f7e81400.i2c
228:          0          0  interrupt-controller   5  f7e81800.i2c
229:          0          0  interrupt-controller   7  dw_spi65535
230:          0          0  interrupt-controller  21  f7e84000.i2c
231:          0          0  interrupt-controller  20  f7e84800.i2c
265:        380          0  interrupt-controller   8  serial
IPI0:          0          0  CPU wakeup interrupts
IPI1:          3          6  Timer broadcast interrupts
IPI2:         60        100  Rescheduling interrupts
IPI3:          0          0  Function call interrupts
IPI4:          0          4  Single function call interrupts
IPI5:          0          0  CPU stop interrupts
IPI6:         21         45  IRQ work interrupts
IPI7:          0          0  completion interrupts
IPI8:          0          0  CPU backtrace
Err:          0

cpu0 got 69-66=3, cpu1 got 75-7=68 timer interrupts. cpu0 got 3-2=1
broadcast timer IPIs, cpu1 got 6-4=2 broadcast timer IPIs.
So, overall system got 3+68+1+2=74 wakeups and 1+2=3 broadcast timer
IPIs

This patch removes 50% wakeups and almost 100% broadcast timer IPIs!

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-10 11:40:53 +02:00
Viresh Kumar
226be92b3e clockevents/drivers/dw_apb: Migrate to new 'set-state' interface
Migrate dw_apb driver to the new 'set-state' interface provided by
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.

Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-10 11:40:28 +02:00
Rusty Russell
f9b531fe14 drivers: fix up obsolete cpu function usage.
Thanks to spatch, plus manual removal of "&*".  Then a sweep for
for_each_cpu_mask => for_each_cpu.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: netdev@vger.kernel.org
2015-03-05 13:37:02 +10:30
Michael Opdenacker
38c30a8421 clocksource: misc drivers: Remove deprecated IRQF_DISABLED
This patch removes the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.

[dlezcano] : slightly changed the changelog

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-12-11 11:40:27 +01:00
John Stultz
d3d8fee413 Revert "dw_apb_timer_of.c: Remove parts that were picoxcell-specific"
This reverts commit 55a68c23e0.

In order to avoid a collision with dw_apb_timer changes in
the arm-soc tree, revert this change.

I'm leaving it to the arm-soc folks to sort out if they want
to keep the other side of the collision or if they're just going
to back it all out and try again during the next release cycle.

Reported-by: Dinh Nguyen <dinguyen@altera.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-06-18 16:02:04 -07:00
Pavel Machek
55a68c23e0 dw_apb_timer_of.c: Remove parts that were picoxcell-specific
It seems we made a mistake when creating dw_apb_timer_of.c:
picoxcell sched_clock had parts that were not related to
dw_apb_timer, yet we moved them to dw_apb_timer_of, and tried to
use them on socfpga.

This results in system where user/system time is not measured
properly, as demonstrated by

    time dd if=/dev/urandom of=/dev/zero bs=100000 count=100

So this patch switches sched_clock to hardware that exists on both
platforms, and adds missing of_node_put() in dw_apb_timer_init().

Signed-off-by: Pavel Machek <pavel@denx.de>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-05-28 14:00:58 -07:00
Thomas Gleixner
fc1f7d5606 clocksource: apb_timer: Remove unsused function
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Link: http://lkml.kernel.org/r/20130425143435.558006195@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-16 11:09:13 +02:00
Jamie Iles
a1330228f9 dw_apb_timer: constify clocksource name
The clocksource name should be const for correctness.

Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-10-04 13:08:18 -07:00
Jamie Iles
06c3df4952 clocksource: apb: Share APB timer code with other platforms
The APB timers are an IP block from Synopsys (DesignWare APB timers)
and are also found in other systems including ARM SoC's.  This patch
adds functions for creating clock_event_devices and clocksources from
APB timers but does not do the resource allocation.  This is handled
in a higher layer to allow the timers to be created from multiple
methods such as platform_devices.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-06-27 15:16:21 -07:00