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2017-04-19clocksource: arm_arch_timer: split dt-only rate handlingFu Wei
For historical reasons, rate detection when probing via DT is somewhat convoluted. We tried to package this up in arch_timer_detect_rate(), but with the addition of ACPI worse, and gets in the way of stringent rate checking when ACPI is used. This patch makes arch_timer_detect_rate() specific to DT, ripping out ACPI logic. In preparation for rework of the MMIO timer probing, the reading of the relevant CNTFRQ register is factored out to callers. The function is then renamed to arch_timer_of_configure_rate(), which better represents its new place in the world. Comments are added in the DT and ACPI probe paths to explain this. Signed-off-by: Fu Wei <fu.wei@linaro.org> [Mark: reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com>
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/atlas7: 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 timer-atlas7 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> Cc: Barry Song <baohua@kernel.org> Cc: linux-arm-kernel@lists.infradead.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>
2017-04-14clockevents/drivers/sh_cmt: 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 sh_cmt 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>
2017-04-14x86/numachip timer: 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 numachip 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>
2017-04-14clockevents/drivers/metag: 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 metag_generic 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> Cc: James Hogan <james.hogan@imgtec.com> 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>
2017-04-14clockevents/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>
2017-04-10clocksource: arm_arch_timer: rework PPI selectionFu Wei
Currently, the arch timer driver uses ARCH_TIMER_PHYS_SECURE_PPI to mean the driver will use the secure PPI *and* potentially also use the non-secure PPI. This is somewhat confusing. For arm64 it never makes sense to use the secure PPI, but we do anyway, inheriting this behaviour from 32-bit arm. For ACPI, we may not even have a valid secure PPI, so we need to be able to only request the non-secure PPI. To that end, this patch reworks the timer driver so that we can request the non-secure PPI alone. The PPI selection is split out into a new function, arch_timer_select_ppi(), and verification of the selected PPI is shifted out to callers (as DT may select the PPI by other means and must handle this anyway). We now consistently use arch_timer_has_nonsecure_ppi() to determine whether we must manage a non-secure PPI *in addition* to a secure PPI. When we only have a non-secure PPI, this returns false. Signed-off-by: Fu Wei <fu.wei@linaro.org> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> [Mark: reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com>
2017-04-10clocksource: arm_arch_timer: add a new enum for spi typeFu Wei
This patch add a new enum "arch_timer_spi_nr" and use it in the driver. Just for code's readability, no functional change. Signed-off-by: Fu Wei <fu.wei@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
2017-04-10clocksource: arm_arch_timer: move enums and defines to header fileFu Wei
To support the arm_arch_timer via ACPI we need to share defines and enums between the driver and the ACPI parser code. So we split out the relevant defines and enums into arm_arch_timer.h. No functional change. Signed-off-by: Fu Wei <fu.wei@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
2017-04-10clocksource: arm_arch_timer: rename the PPI enumFu Wei
In preparation for moving the PPI enum out into a header, rename the enum and its constituent values these so they are namespaced w.r.t. the arch timer. This will aid consistency and avoid potential name clashes when this move occurs. No functional change. Signed-off-by: Fu Wei <fu.wei@linaro.org> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> [Mark: reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com>
2017-04-10clocksource: arm_arch_timer: rename type macrosFu Wei
In preparation for moving the type macros out into a header, rename these so they are namespaced w.r.t. the arch timer. We'll apply the same prefix to other definitions in subsequent patches. This will aid consistency and avoid potential name clahses when this move occurs. No functional change. Signed-off-by: Fu Wei <fu.wei@linaro.org> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> [Mark: reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com>
2017-04-10clocksource: arm_arch_timer: clean up printk usageFu Wei
Almost all string in the arm_arch_timer driver duplicate an common prefix (though a few do not). For consistency, it would be better to use pr_fmt(), and always use this prefix. At the same time, we may as well clean up some whitespace issues in arch_timer_banner and arch_timer_init. No functional change. Signed-off-by: Fu Wei <fu.wei@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> [Mark: reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com>
2017-04-07Merge tag 'arch-timer-errata' of ↵Daniel Lezcano
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into clockevents/4.12 arm64 arch timer workaround series, including the base patches that will also go via the arm64 tree. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-04-07clocksource/drivers/fttmr010: Refactor to handle clockLinus Walleij
The plain Faraday FTTMR010 timer needs a clock to figure out its tick rate, and the gemini reads it directly from the system controller set-up. Split the init function and add two paths for the two compatible-strings. We only support clocking using PCLK because of lack of documentation on how EXTCLK works. The Gemini still works like before, but we can also support a generic, clock-based version. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-04-07clocksource/drivers/gemini: Rename Gemini timer to FaradayLinus Walleij
After some research it turns out that the "Gemini" timer is actually a generic IP block from Faraday Technology named FTTMR010, so as to not make things too confusing we need to rename the driver and its symbols to make sense. The implementation remains the same in this patch but we fix the copy-paste error in the timer name "nomadik_mtu" as we're at it. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-04-07clocksource/drivers/rockchip_timer: Implement clocksource timerAlexander Kochetkov
The clock supplying the arm-global-timer on the rk3188 is coming from the the cpu clock itself and thus changes its rate everytime cpufreq adjusts the cpu frequency making this timer unsuitable as a stable clocksource and sched clock. The rk3188, rk3288 and following socs share a separate timer block already handled by the rockchip-timer driver. Therefore adapt this driver to also be able to act as clocksource and sched clock on rk3188. In order to test clocksource you can run following commands and check how much time it take in real. On rk3188 it take about ~45 seconds. cpufreq-set -f 1.6GHZ date; sleep 60; date In order to use the patch you need to declare two timers in the dts file. The first timer will be initialized as clockevent provider and the second one as clocksource. The clockevent must be from alive subsystem as it used as backup for the local timers at sleep time. The patch does not break compatibility with older device tree files. The older device tree files contain only one timer. The timer will be initialized as clockevent, as expected. rk3288 (and probably anything newer) is irrelevant to this patch, as it has the arch timer interface. This patch may be useful for Cortex-A9/A5 based parts. Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@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>
2017-04-07clocksource/drivers/orion: Add delay_timer implementationRussell King
Add an implementation for the ARM delay timer, which is used for udelay(). This provides less CPU dependent and more accurate delays - the CPU loop on Marvell Dove appears to calibrate to around 6% too short. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-04-07clocksource/drivers/orion: Read clock rate onceRussell King
Rather than reading the clock rate three times, read it once - we are about to add a fourth usage. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-04-07arm64: arch_timer: Add HISILICON_ERRATUM_161010101 ACPI matching dataMarc Zyngier
In order to deal with ACPI enabled platforms suffering from the HISILICON_ERRATUM_161010101, let's add the required OEM data that allow the workaround to be enabled. Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: dann frazier <dann.frazier@canonical.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Allow erratum matching with ACPI OEM informationMarc Zyngier
Just as we're able to identify a broken platform using some DT information, let's enable a way to spot the offenders with ACPI. The difference is that we can only match on some OEM info instead of implementation-specific properties. So in order to avoid the insane multiplication of errata structures, we allow an array of OEM descriptions to be attached to an erratum structure. Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: dann frazier <dann.frazier@canonical.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Workaround for Cortex-A73 erratum 858921Marc Zyngier
Cortex-A73 (all versions) counter read can return a wrong value when the counter crosses a 32bit boundary. The workaround involves performing the read twice, and to return one or the other depending on whether a transition has taken place. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Enable CNTVCT_EL0 trap if workaround is enabledMarc Zyngier
Userspace being allowed to use read CNTVCT_EL0 anytime (and not only in the VDSO), we need to enable trapping whenever a cntvct workaround is enabled on a given CPU. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Save cntkctl_el1 as a per-cpu variableMarc Zyngier
As we're about to allow per CPU cntkctl_el1 configuration, we cannot rely on the register value to be common when performing power management. Let's turn saved_cntkctl into a per-cpu variable. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Move clocksource_counter and co aroundMarc Zyngier
In order to access clocksource_counter from the errata handling code, move it (together with the related structures and functions) towards the top of the file. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Allows a CPU-specific erratum to only affect a subset of CPUsMarc Zyngier
Instead of applying a CPU-specific workaround to all CPUs in the system, allow it to only affect a subset of them (typical big-little case). This is done by turning the erratum pointer into a per-CPU variable. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Rework the set_next_event workaroundsMarc Zyngier
The way we work around errata affecting set_next_event is not very nice, at it imposes this workaround on errata that do not need it. Add new workaround hooks and let the existing workarounds use them. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Get rid of erratum_workaround_set_sneMarc Zyngier
Let's move the handling of workarounds affecting set_next_event to the affected function, instead of overriding the pointers as an afterthough. Yes, this is an extra indirection on the erratum handling path, but the HW is busted anyway. This will allow for some more flexibility later. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Move arch_timer_reg_read/write aroundMarc Zyngier
As we're about to move things around, let's start with the low level read/write functions. This allows us to use these functions in the errata handling code without having to use forward declaration of static functions. Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Add erratum handler for CPU-specific capabilityMarc Zyngier
Should we ever have a workaround for an erratum that is detected using a capability and affecting a particular CPU, it'd be nice to have a way to probe them directly. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07arm64: arch_timer: Add infrastructure for multiple erratum detection methodsMarc Zyngier
We're currently stuck with DT when it comes to handling errata, which is pretty restrictive. In order to make things more flexible, let's introduce an infrastructure that could support alternative discovery methods. No change in functionality. Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-02Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "Two small fixes for the new CLKEVT_OF infrastructure" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: vmlinux.lds: Add __clkevt_of_table to kernel clockevents: Fix syntax error in clkevt-of macro
2017-03-28clockevents: Fix syntax error in clkevt-of macroAlexander Kochetkov
The patch fix syntax errors introduced by commit 0c8893c9095d ("clockevents: Add a clkevt-of mechanism like clksrc-of"). Fixes: 0c8893c9095d ("clockevents: Add a clkevt-of mechanism like clksrc-of") Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-03-23clocksource: h8300_timer8: Don't reset rate in ->set_state_oneshot()Nicolai Stange
With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, h8300_timer8 violates this requirement in that it registers its clockevent device with the correct rate, but resets its ->mult and ->rate values in timer8_clock_event_start(), called from its ->set_state_oneshot() function. It seems like commit 4633f4cac85a ("clocksource/drivers/h8300: Cleanup startup and remove module code."), which introduced the rate initialization at registration, missed to remove the manual setting of ->mult and ->shift from timer8_clock_event_start(). Purge the setting of ->mult, ->shift, ->min_delta_ns and ->max_delta_ns from timer8_clock_event_start(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-03-23clocksource: em_sti: Compute rate before registrationNicolai Stange
With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, em_sti violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot(). This patch moves the setting of the clockevent device's rate to its registration. I checked all current em_sti users in arch/arm/mach-shmobile and right now, none of them changes any rate in any clock tree relevant to em_sti after their respective time_init(). Since all em_sti instances are created after time_init(), none of them should ever observe any clock rate changes. - Determine the ->rate value in em_sti_probe() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-03-23clocksource: em_sti: Split clock prepare and enable stepsNicolai Stange
Currently, the em_sti driver prepares and enables the needed clock in em_sti_enable(), potentially called through its clockevent device's ->set_state_oneshot(). However, the clk_prepare() step may sleep whereas tick_program_event() and thus, ->set_state_oneshot(), can be called in atomic context. Split the clk_prepare_enable() in em_sti_enable() into two steps: - prepare the clock at device probing via clk_prepare() - and enable it in em_sti_enable() via clk_enable(). Slightly reorder resource initialization in em_sti_probe() in order to facilitate error handling in later patches. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-03-23clocksource: sh_tmu: Compute rate before registration againNicolai Stange
With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_tmu violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's rate to its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit 66f49121ffa4 ("clocksource: sh_tmu: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 0aeac458d9eb ("clocksource: sh_tmu: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_tmu users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_tmu after their respective time_init(). Since all sh_tmu instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device: it's a property of the underlying clock which is in turn specific to the sh_tmu_device. - Determine the ->rate value in sh_tmu_setup() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-03-23clocksource: sh_cmt: Compute rate before registration againNicolai Stange
With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_cmt violates this requirement in that it registers its clockevent device with a dummy rate and sets its final ->mult and ->shift values from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's ->mult and ->shift values to before its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit f4d7c3565c16 ("clocksource: sh_cmt: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 3593f5fe40a1 ("clocksource: sh_cmt: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_cmt users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_cmt after their respective time_init(). Since all sh_cmt instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_cmt_channel's ->rate member to struct sh_cmt_device: it's a property of the underlying clock which is in turn specific to the sh_cmt_device. - Determine the ->rate value in sh_cmt_setup() at device probing rather than at first usage. - Set the clockevent device's ->mult and ->shift values right before its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-03-17Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "Just a simple revert of a new sched_clock implementation which turned out to be buggy" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock"
2017-03-11Revert "clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock"Romain Izard
This reverts commit 7b9f1d16e6d1 ("clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock"). In the current state, the kernel warns against a late registration of the new sched_clock, the printk clock resets after only a few minutes, and it seems that scheduling can be affected as well. Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/clock.h> We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which will have to be picked up from other headers and .c files. Create a trivial placeholder <linux/sched/clock.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-20Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Nothing exciting, just the usual pile of fixes, updates and cleanups: - A bunch of clocksource driver updates - Removal of CONFIG_TIMER_STATS and the related /proc file - More posix timer slim down work - A scalability enhancement in the tick broadcast code - Math cleanups" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) hrtimer: Catch invalid clockids again math64, tile: Fix build failure clocksource/drivers/arm_arch_timer:: Mark cyclecounter __ro_after_init timerfd: Protect the might cancel mechanism proper timer_list: Remove useless cast when printing time: Remove CONFIG_TIMER_STATS clocksource/drivers/arm_arch_timer: Work around Hisilicon erratum 161010101 clocksource/drivers/arm_arch_timer: Introduce generic errata handling infrastructure clocksource/drivers/arm_arch_timer: Remove fsl-a008585 parameter clocksource/drivers/arm_arch_timer: Add dt binding for hisilicon-161010101 erratum clocksource/drivers/ostm: Add renesas-ostm timer driver clocksource/drivers/ostm: Document renesas-ostm timer DT bindings clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock clocksource/drivers/gemini: Add driver for the Cortina Gemini clocksource: add DT bindings for Cortina Gemini clockevents: Add a clkevt-of mechanism like clksrc-of tick/broadcast: Reduce lock cacheline contention timers: Omit POSIX timer stuff from task_struct when disabled x86/timer: Make delay() work during early bootup delay: Add explanation of udelay() inaccuracy ...
2017-02-11clocksource/drivers/arm_arch_timer:: Mark cyclecounter __ro_after_initBhumika Goyal
The object cyclecounter of type cyclecounter is only modified during initialization in arch_counter_register. So it can be marked __ro_after_init. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Cc: mark.rutland@arm.com Cc: keescook@chromium.org Cc: marc.zyngier@arm.com Cc: daniel.lezcano@linaro.org Cc: julia.lawall@lip6.fr Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1486840818-22214-1-git-send-email-bhumirks@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-08clocksource/drivers/arm_arch_timer: Work around Hisilicon erratum 161010101Ding Tianhong
Erratum Hisilicon-161010101 says that the ARM generic timer counter "has the potential to contain an erroneous value when the timer value changes". Accesses to TVAL (both read and write) are also affected due to the implicit counter read. Accesses to CVAL are not affected. The workaround is to reread the system count registers until the value of the second read is larger than the first one by less than 32, the system counter can be guaranteed not to return wrong value twice by back-to-back read and the error value is always larger than the correct one by 32. Writes to TVAL are replaced with an equivalent write to CVAL. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> [Mark: split patch, fix Kconfig, reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-02-08clocksource/drivers/arm_arch_timer: Introduce generic errata handling ↵Ding Tianhong
infrastructure Currently we have code inline in the arch timer probe path to cater for Freescale erratum A-008585, complete with ifdeffery. This is a little ugly, and will get worse as we try to add more errata handling. This patch refactors the handling of Freescale erratum A-008585. Now the erratum is described in a generic arch_timer_erratum_workaround structure, and the probe path can iterate over these to detect errata and enable workarounds. This will simplify the addition and maintenance of code handling Hisilicon erratum 161010101. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> [Mark: split patch, correct Kconfig, reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-02-08clocksource/drivers/arm_arch_timer: Remove fsl-a008585 parameterDing Tianhong
Having a command line option to flip the errata handling for a particular erratum is a little bit unusual, and it's vastly superior to pass this in the DT. By common consensus, it's best to kill off the command line parameter. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> [Mark: split patch, reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-02-07clocksource/drivers/ostm: Add renesas-ostm timer driverChris Brandt
This patch adds a OSTM driver for the Renesas architecture. The OS Timer (OSTM) has independent channels that can be used as a freerun or interval times. This driver uses the first probed device as a clocksource and then any additional devices as clock events. Signed-off-by: Chris Brandt <chris.brandt@renesas.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-02-07clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clockDavid Engraf
On newer boards the TC can be read as single 32 bit value without locking. Thus the clock can be used as reference for sched_clock which is much more accurate than the jiffies implementation. Tested on a Atmel SAMA5D2 board. Signed-off-by: David Engraf <david.engraf@sysgo.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-02-07clocksource/drivers/gemini: Add driver for the Cortina GeminiLinus Walleij
This is a rewrite of the Gemini timer driver in arch/arm/mach-gemini/timer.c trying to do everything the device tree way: - Make every IO-access relative to a base address and dynamic so we can do a dynamic ioremap and get going. - Do not poke around directly in the global syscon registers, access them using the syscon regmap style design pattern for the one register we need to check. - Find register range and interrupt from the device tree. Cc: Janos Laube <janos.dev@gmail.com> Cc: Paulius Zaleckas <paulius.zaleckas@gmail.com> Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>