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path: root/drivers/clocksource/dw_apb_timer.c
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2020-05-23clocksource: dw_apb_timer: Make CPU-affiliation being optionalSerge Semin
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
2020-02-27clocksource: Replace setup_irq() by request_irq()afzal mohammed
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
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
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>
2017-04-17Merge branch 'clockevents/4.12' of ↵Thomas Gleixner
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)
2017-04-14clockevents/drivers/dw_apb: Set ->min_delta_ticks and ->max_delta_ticksNicolai Stange
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>
2017-04-07clocksource: Add missing line break to error messagesRafał Miłecki
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>
2016-12-25clocksource: Use a plain u64 instead of cycle_tThomas Gleixner
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>
2016-04-28clockevents/drivers/dw_apb_timer: Implement ->set_state_oneshot_stopped()Jisheng Zhang
The dw_apb_timer only "supports PERIODIC mode and their drivers emulate ONESHOT over that" as described in commit 8fff52fd5093 ("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>
2015-12-15clocksource/drivers/dw_apb_timer: Inline apbt_readl and apbt_writelJisheng Zhang
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>
2015-12-15clocksource/drivers/dw_apb_timer: Use {readl|writel}_relaxed in critical pathJisheng Zhang
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>
2015-12-15clocksource/drivers/dw_apb_timer: Fix apbt_readl return typesJisheng Zhang
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>
2015-08-10clockevents/drivers/dw_apb_timer: Add dynamic irq flag to the timerJisheng Zhang
Commit d2348fb6fdc6 ("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>
2015-08-10clockevents/drivers/dw_apb: Migrate to new 'set-state' interfaceViresh Kumar
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>
2015-03-05drivers: fix up obsolete cpu function usage.Rusty Russell
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
2013-12-11clocksource: misc drivers: Remove deprecated IRQF_DISABLEDMichael Opdenacker
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>
2013-06-18Revert "dw_apb_timer_of.c: Remove parts that were picoxcell-specific"John Stultz
This reverts commit 55a68c23e0a675b2b8ac2656fd6edbf98b78e4c6. 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>
2013-05-28dw_apb_timer_of.c: Remove parts that were picoxcell-specificPavel Machek
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>
2013-05-16clocksource: apb_timer: Remove unsused functionThomas Gleixner
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>
2011-10-04dw_apb_timer: constify clocksource nameJamie Iles
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>
2011-06-27clocksource: apb: Share APB timer code with other platformsJamie Iles
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>