linux/drivers/clocksource/arm_arch_timer.c, branch v3.18

ARM/ARM64: arch-timer: fix arch_timer_probed logic

2014-10-26T19:50:00Z

Commit c387f07e6205 (clocksource: arm_arch_timer: Discard unavailable timers correctly) changed the way the driver makes sure both the memory and system-register timers have been probed before finalizing the probing. There is a interesting flaw in this logic that leads to this final step never to be executed. Things seems to work pretty well until something actually needs the data that is produced during this final stage. For example, KVM explodes on the first run of a guest when executed on a platform that has both memory and sysreg nodes (Juno, for example). Just fix the damned logic, and enjoy booting VMs again. Tested on a Juno system. Cc: Sudeep Holla Cc: Stephen Boyd Cc: Mark Rutland Cc: Daniel Lezcano Cc: Christoffer Dall Reported-by: Riku Voipio Acked-by: Mark Rutland Acked-by: Sudeep Holla Tested-by: Sudeep Holla Signed-off-by: Marc Zyngier Signed-off-by: Daniel Lezcano

clocksource: arm_arch_timer: Consolidate arch_timer_evtstrm_enable

2014-09-28T23:59:26Z

The arch_timer_evtstrm_enable hooks in arm and arm64 are substantially similar, the only difference being a CONFIG_COMPAT-conditional section which is relevant only for arm64. Copy the arm64 version to the driver, removing the arch-specific hooks. Signed-off-by: Nathan Lynch Signed-off-by: Daniel Lezcano Acked-by: Will Deacon

clocksource: arm_arch_timer: Enable counter access for 32-bit ARM

2014-09-28T23:59:25Z

The only difference between arm and arm64's implementations of arch_counter_set_user_access is that 32-bit ARM does not enable user access to the virtual counter. We want to enable this access for the 32-bit ARM VDSO, so copy the arm64 version to the driver itself, and remove the arch-specific implementations. Signed-off-by: Nathan Lynch Signed-off-by: Daniel Lezcano Acked-by: Will Deacon

clocksource: arm_arch_timer: Change clocksource name if CP15 unavailable

2014-09-28T23:59:24Z

The arm and arm64 VDSOs need CP15 access to the architected counter. If this is unavailable (which is allowed by ARM v7), indicate this by changing the clocksource name to "arch_mem_counter" before registering the clocksource. Suggested by Stephen Boyd. Signed-off-by: Nathan Lynch Reviewed-by: Stephen Boyd Signed-off-by: Daniel Lezcano Acked-by: Will Deacon

clocksource: arm_arch_timer: Discard unavailable timers correctly

2014-09-28T23:50:05Z

Currently we wait until both cp15 and mem timers are probed if we have both timer device nodes present in the device tree without checking if the device is actually available. If one of the timer device node present is disabled, the system locks up on the boot as no timer gets registered. This patch adds the check for the availability of the timer device so that unavailable timers are discarded correctly. It also adds the missing of_node_put. Signed-off-by: Sudeep Holla Reviewed-by: Stephen Boyd Acked-by: Mark Rutland Signed-off-by: Daniel Lezcano

clocksource: arch_arm_timer: Fix age-old arch timer C3STOP detection issue

2014-04-29T13:06:36Z

ARM arch timers are tightly coupled with the CPU logic and lose context on platform implementing HW power management when cores are powered down at run-time. Marking the arch timers as C3STOP regardless of power management capabilities causes issues on platforms with no power management, since in that case the arch timers cannot possibly enter states where the timer loses context at runtime and therefore can always be used as a high resolution clockevent device. In order to fix the C3STOP issue in a way compliant with how real HW works, this patch adds a boolean property to the arch timer bindings to define if the arch timer is managed by an always-on power domain. This power domain is present on all ARM platforms to date, and manages HW that must not be turned off, whatever the state of other HW components (eg power controller). On platforms with no power management capabilities, it is the only power domain present, which encompasses and manages power supply for all HW components in the system. If the timer is powered by the always-on power domain, the always-on property must be present in the bindings which means that the timer cannot be shutdown at runtime, so it is not a C3STOP clockevent device. If the timer binding does not contain the always-on property, the timer is assumed to be power-gateable, hence it must be defined as a C3STOP clockevent device. Cc: Daniel Lezcano Cc: Magnus Damm Cc: Marc Carino Cc: Mark Rutland Acked-by: Marc Zyngier Acked-by: Rob Herring Signed-off-by: Lorenzo Pieralisi Signed-off-by: Daniel Lezcano

clocksource: arch_timer: Set dynamic irq affinity on mmio clockevent

2014-03-11T22:04:39Z

Set the CLOCK_EVT_FEAT_DYNIRQ flag on the memory mapped clockevent so that we save power by waking up the CPU with the next event when this timer is used in broadcast mode. Signed-off-by: Stephen Boyd Signed-off-by: Daniel Lezcano

clocksource: arch_timer: Do not register arch_sys_counter twice

2013-10-16T06:30:03Z

Commit: 65cd4f6 ("arch_timer: Move to generic sched_clock framework") added code to register the arch_sys_counter in arch_timer_register(), but it is already registered in arch_counter_register(). This results in the timer being added to the clocksource list twice, therefore causing an infinite loop in the list. Remove the duplicate registration and register the scheduler clock after the original registration instead. This fixes a hang during boot on Tegra114 (Cortex-A15). [ While I've only tested this on Tegra114, I suspect the same hang during boot happens for all processors that use this clock source. ] Signed-off-by: Thierry Reding Acked-by: John Stultz Cc: Stephen Boyd Cc: Will Deacon Cc: Stephen Warren Cc: linux-arm-kernel@lists.infradead.org Cc: Daniel Lezcano Link: http://lkml.kernel.org/r/1381843911-31962-1-git-send-email-treding@nvidia.com Signed-off-by: Ingo Molnar

Merge branch 'fortglx/3.13/time' of git://git.linaro.org/people/jstultz/linux into timers/core

2013-10-10T04:25:23Z

Pull more timekeeping items for v3.13 from John Stultz: * Small cleanup in the clocksource code. * Fix for rtc-pl031 to let it work with alarmtimers. * Move arm64 to using the generic sched_clock framework & resulting cleanup in the generic sched_clock code. Signed-off-by: Ingo Molnar

arch_timer: Move to generic sched_clock framework

2013-10-09T23:54:10Z

Register with the generic sched_clock framework now that it supports 64 bits. This fixes two problems with the current sched_clock support for machines using the architected timers. First off, we don't subtract the start value from subsequent sched_clock calls so we can potentially start off with sched_clock returning gigantic numbers. Second, there is no support for suspend/resume handling so problems such as discussed in 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during suspend, 2012-10-23) can happen without this patch. Finally, it allows us to move the sched_clock setup into drivers clocksource out of the arch ports. Cc: Christopher Covington Cc: Catalin Marinas Acked-by: Will Deacon Signed-off-by: Stephen Boyd Signed-off-by: John Stultz