kernel/drivers/clocksource/exynos_mct.c, branch linux-5.1.y

clocksource/drivers/exynos_mct: Increase priority over ARM arch timer

2019-07-26T07:12:43Z

[ Upstream commit 6282edb72bed5324352522d732080d4c1b9dfed6 ] Exynos SoCs based on CA7/CA15 have 2 timer interfaces: custom Exynos MCT (Multi Core Timer) and standard ARM Architected Timers. There are use cases, where both timer interfaces are used simultanously. One of such examples is using Exynos MCT for the main system timer and ARM Architected Timers for the KVM and virtualized guests (KVM requires arch timers). Exynos Multi-Core Timer driver (exynos_mct) must be however started before ARM Architected Timers (arch_timer), because they both share some common hardware blocks (global system counter) and turning on MCT is needed to get ARM Architected Timer working properly. To ensure selecting Exynos MCT as the main system timer, increase MCT timer rating. To ensure proper starting order of both timers during suspend/resume cycle, increase MCT hotplug priority over ARM Archictected Timers. Signed-off-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Reviewed-by: Chanwoo Choi Signed-off-by: Daniel Lezcano Signed-off-by: Sasha Levin

clocksource/drivers/exynos_mct: Remove unused header includes

2019-02-23T11:13:45Z

The driver does not use sched.h and platform_device.h. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Daniel Lezcano

clocksource/drivers/exynos_mct: Fix error path in timer resources initialization

2019-02-23T11:13:45Z

While freeing interrupt handlers in error path, don't assume that all requested interrupts are per-processor interrupts and properly release standard interrupts too. Reported-by: Krzysztof Kozlowski Fixes: 56a94f13919c ("clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier") Signed-off-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Reviewed-by: Chanwoo Choi Signed-off-by: Daniel Lezcano

clocksource/drivers/exynos_mct: Remove dead code

2019-02-23T11:13:45Z

Exynos Multi-Core Timer driver is used only on device-tree based systems, so remove non-dt related code. In case of !CONFIG_OF the code is anyway equal because of_irq_count() has a stub returning 0. Device node pointer is always provided when driver has been probed from device tree. Signed-off-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Reviewed-by: Chanwoo Choi Signed-off-by: Daniel Lezcano

clocksource/drivers/exynos_mct: Clear timer interrupt when shutdown

2019-02-23T11:13:45Z

When shutting down the timer, ensure that after we have stopped the timer any pending interrupts are cleared. This fixes a problem when suspending, as interrupts are disabled before the timer is stopped, so the timer interrupt may still be asserted, preventing the system entering a low power state when the wfi is executed. Signed-off-by: Stuart Menefy Reviewed-by: Krzysztof Kozlowski Tested-by: Marek Szyprowski Cc: # v4.3+ Signed-off-by: Daniel Lezcano

clocksource/drivers/exynos_mct: Move one-shot check from tick clear to ISR

2019-02-23T11:13:45Z

When a timer tick occurs and the clock is in one-shot mode, the timer needs to be stopped to prevent it triggering subsequent interrupts. Currently this code is in exynos4_mct_tick_clear(), but as it is only needed when an ISR occurs move it into exynos4_mct_tick_isr(), leaving exynos4_mct_tick_clear() just doing what its name suggests it should. Signed-off-by: Stuart Menefy Reviewed-by: Krzysztof Kozlowski Tested-by: Marek Szyprowski Cc: stable@vger.kernel.org # v4.3+ Signed-off-by: Daniel Lezcano

clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE

2017-06-14T09:58:45Z

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/exynos_mct: Clear interrupt when cpu is shut down

2017-01-17T09:08:38Z

When a CPU goes offline a potentially pending timer interrupt is not cleared. When the CPU comes online again then the pending interrupt is delivered before the per cpu clockevent device is initialized. As a consequence the tick interrupt handler dereferences a NULL pointer. [ 51.251378] Unable to handle kernel NULL pointer dereference at virtual address 00000040 [ 51.289348] task: ee942d00 task.stack: ee960000 [ 51.293861] PC is at tick_periodic+0x38/0xb0 [ 51.298102] LR is at tick_handle_periodic+0x1c/0x90 Clear the pending interrupt in the cpu dying path. Fixes: 56a94f13919c ("clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier") Reported-by: Seung-Woo Kim Signed-off-by: Joonyoung Shim Cc: linux-samsung-soc@vger.kernel.org Cc: cw00.choi@samsung.com Cc: daniel.lezcano@linaro.org Cc: stable@vger.kernel.org Cc: javier@osg.samsung.com Cc: kgene@kernel.org Cc: krzk@kernel.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1484628876-22065-1-git-send-email-jy0922.shim@samsung.com Signed-off-by: Thomas Gleixner

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-25T22:30:04Z

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

clocksource: Use a plain u64 instead of cycle_t

2016-12-25T10:04:12Z

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 Cc: Peter Zijlstra Cc: John Stultz