linux/drivers/clocksource/arm_arch_timer.c, branch v4.9

arm/arm64: arch_timer: Use archdata to indicate vdso suitability

2016-09-23T16:19:25Z

Instead of comparing the name to a magic string, use archdata to explicitly communicate whether the arch timer is suitable for direct vdso access. Acked-by: Will Deacon Acked-by: Russell King Acked-by: Marc Zyngier Signed-off-by: Scott Wood Signed-off-by: Will Deacon

arm64: arch_timer: Work around QorIQ Erratum A-008585

2016-09-23T16:19:25Z

Erratum A-008585 says that the ARM generic timer counter "has the potential to contain an erroneous value for a small number of core clock cycles every time 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 TVAL and count registers until successive reads return the same value. Writes to TVAL are replaced with an equivalent write to CVAL. The workaround is to reread TVAL and count registers until successive reads return the same value, and when writing TVAL to retry until counter reads before and after the write return the same value. The workaround is enabled if the fsl,erratum-a008585 property is found in the timer node in the device tree. This can be overridden with the clocksource.arm_arch_timer.fsl-a008585 boot parameter, which allows KVM users to enable the workaround until a mechanism is implemented to automatically communicate this information. This erratum can be found on LS1043A and LS2080A. Acked-by: Marc Zyngier Signed-off-by: Scott Wood [will: renamed read macro to reflect that it's not usually unstable] Signed-off-by: Will Deacon

clocksource/arm_arch_timer: Force per-CPU interrupt to be level-triggered

2016-08-01T14:15:53Z

The ARM architected timer produces level-triggered interrupts (this is mandated by the architecture). Unfortunately, a number of device-trees get this wrong, and expose an edge-triggered interrupt. Until now, this wasn't too much an issue, as the programming of the trigger would fail (the corresponding PPI cannot be reconfigured), and the kernel would be happy with this. But we're about to change this, and trust DT a lot if the driver doesn't provide its own trigger information. In that context, the timer breaks badly. While we do need to fix the DTs, there is also some userspace out there (kvmtool) that generates the same kind of broken DT on the fly, and that will completely break with newer kernels. As a safety measure, and to keep buggy software alive as well as buying us some time to fix DTs all over the place, let's check what trigger configuration has been given us by the firmware. If this is not a level configuration, then we know that the DT/ACPI configuration is bust, and we pick some defaults which won't be worse than the existing setup. Signed-off-by: Marc Zyngier Cc: Andrew Lunn Cc: Liu Gang Cc: Mark Rutland Cc: Masahiro Yamada Cc: Wenbin Song Cc: Mingkai Hu Cc: Florian Fainelli Cc: Kevin Hilman Cc: Daniel Lezcano Cc: Michal Simek Cc: Jon Hunter Cc: arm@kernel.org Cc: bcm-kernel-feedback-list@broadcom.com Cc: linux-arm-kernel@lists.infradead.org Cc: Sebastian Hesselbarth Cc: Jason Cooper Cc: Ray Jui Cc: "Hou Zhiqiang" Cc: Tirumalesh Chalamarla Cc: linux-samsung-soc@vger.kernel.org Cc: Yuan Yao Cc: Jan Glauber Cc: Gregory Clement Cc: linux-amlogic@lists.infradead.org Cc: soren.brinkmann@xilinx.com Cc: Rajesh Bhagat Cc: Scott Branden Cc: Duc Dang Cc: Kukjin Kim Cc: Carlo Caione Cc: Dinh Nguyen Link: http://lkml.kernel.org/r/1470045256-9032-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner

clocksource/arm_arch_timer: Convert to hotplug state machine

2016-07-15T08:40:24Z

Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Richard Cochran Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: Daniel Lezcano Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153336.048259040@linutronix.de Signed-off-by: Ingo Molnar

clocksource/drivers/arm_arch_timer: Control the evtstrm via the cmdline

2016-06-28T09:35:50Z

Disabling the eventstream can be useful for both remotely debugging a deployed production system and development of code using WFE-based polling loops. Whilst this can currently be controlled via a Kconfig option (CONFIG_ARM_ARCH_TIMER_EVTSTREAM), it's often desirable to toggle the feature on the command line, so this patch adds a new command-line option ("clocksource.arm_arch_timer.evtstrm") to do just that. The default behaviour is determined based on CONFIG_ARM_ARCH_TIMER_EVTSTREAM. Cc: Marc Zyngier Cc: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Daniel Lezcano

clocksources: Switch back to the clksrc table

2016-06-28T08:19:35Z

All the clocksource drivers's init function are now converted to return an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the clksrc-of table. Let's convert back the names: - CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE - clksrc-of-ret => clksrc-of Signed-off-by: Daniel Lezcano For exynos_mct and samsung_pwm_timer: Acked-by: Krzysztof Kozlowski For arch/arc: Acked-by: Vineet Gupta For mediatek driver: Acked-by: Matthias Brugger For the Rockchip-part Acked-by: Heiko Stuebner For STi : Acked-by: Patrice Chotard For the mps2-timer.c and versatile.c changes: Acked-by: Liviu Dudau For the OXNAS part : Acked-by: Neil Armstrong For LPC32xx driver: Acked-by: Sylvain Lemieux For Broadcom Kona timer change: Acked-by: Ray Jui For Sun4i and Sun5i: Acked-by: Chen-Yu Tsai For Meson6: Acked-by: Carlo Caione For Keystone: Acked-by: Santosh Shilimkar For NPS: Acked-by: Noam Camus For bcm2835: Acked-by: Eric Anholt

clocksource/drivers/arm_arch_timer: Convert init function to return error

2016-06-28T08:19:22Z

The init functions do not return any error. They behave as the following: - panic, thus leading to a kernel crash while another timer may work and make the system boot up correctly or - print an error and let the caller unaware if the state of the system Change that by converting the init functions to return an error conforming to the CLOCKSOURCE_OF_RET prototype. Proper error handling (rollback, errno value) will be changed later case by case, thus this change just return back an error or success in the init function. Signed-off-by: Daniel Lezcano

clocksource: arm_arch_timer: Remove arch_timer_get_timecounter

2016-05-03T10:54:21Z

The only call of arch_timer_get_timecounter (in KVM) has been removed. Signed-off-by: Julien Grall Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall

clocksource: arm_arch_timer: Extend arch_timer_kvm_info to get the virtual IRQ

2016-05-03T10:54:21Z

Currently, the firmware table is parsed by the virtual timer code in order to retrieve the virtual timer interrupt. However, this is already done by the arch timer driver. To avoid code duplication, extend arch_timer_kvm_info to get the virtual IRQ. Note that the KVM code will be modified in a subsequent patch. Signed-off-by: Julien Grall Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall

clocksource: arm_arch_timer: Gather KVM specific information in a structure

2016-05-03T10:54:20Z

Introduce a structure which are filled up by the arch timer driver and used by the virtual timer in KVM. The first member of this structure will be the timecounter. More members will be added later. A stub for the new helper isn't introduced because KVM requires the arch timer for both ARM64 and ARM32. The function arch_timer_get_timecounter is kept for the time being and will be dropped in a subsequent patch. Signed-off-by: Julien Grall Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall