kernel/linux.git/include/clocksource/arm_arch_timer.h, branch v6.6.132

KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer

2023-03-30T18:01:09+00:00

With ECV and CNTPOFF_EL2, it is very easy to offer an offset for the physical timer. So let's do just that. Nothing can set the offset yet, so this should have no effect whatsoever (famous last words...). Reviewed-by: Colton Lewis Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230330174800.2677007-5-maz@kernel.org

clocksource/drivers/arm_arch_timer: Use event stream scaling when available

2022-03-07T17:27:22+00:00

With FEAT_ECV and the 1GHz counter, it is pretty likely that the event stream divider doesn't fit in the field that holds the divider value (we only have 4 bits to describe counter bits [15:0] Thankfully, FEAT_ECV also provides a scaling mechanism to switch the field to cover counter bits [23:8] instead. Enable this on arm64 when ECV is available (32bit doesn't have any detection infrastructure and is unlikely to be run on an ARMv8.6 system anyway). Signed-off-by: Marc Zyngier Cc: Mark Rutland Cc: Daniel Lezcano Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20220203170502.2694422-1-maz@kernel.org Signed-off-by: Daniel Lezcano

clocksource/drivers/arm_arch_timer: Remove any trace of the TVAL programming interface

2021-10-17T19:47:39+00:00

TVAL usage is now long gone, get rid of the leftovers. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211017124225.3018098-11-maz@kernel.org Signed-off-by: Daniel Lezcano

clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL

2021-10-17T19:47:05+00:00

In order to cope better with high frequency counters, move the programming of the timers from the countdown timer (TVAL) over to the comparator (CVAL). The programming model is slightly different, as we now need to read the current counter value to have an absolute deadline instead of a relative one. There is a small overhead to this change, which we will address in the following patches. Reviewed-by: Oliver Upton Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211017124225.3018098-5-maz@kernel.org Signed-off-by: Daniel Lezcano

arm64: arch_timer: Implement support for interrupt-names

2021-04-08T11:18:38+00:00

This allows the devicetree to correctly represent the available set of timers, which varies from device to device, without the need for fake dummy interrupts for unavailable slots. Also add the hyp-virt timer/PPI, which is not currently used, but worth representing. Reviewed-by: Tony Lindgren Reviewed-by: Linus Walleij Reviewed-by: Marc Zyngier Signed-off-by: Hector Martin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

2019-06-19T15:09:07+00:00

Based on 1 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 distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Reviewed-by: Enrico Weigelt Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman

clocksource/arm_arch_timer: Store physical timer IRQ number for KVM on VHE

2019-02-19T21:05:22+00:00

A host running in VHE mode gets the EL2 physical timer as its time source (accessed using the EL1 sysreg accessors, which get re-directed to the EL2 sysregs by VHE). The EL1 physical timer remains unused by the host kernel, allowing us to pass that on directly to a KVM guest and saves us from emulating this timer for the guest on VHE systems. Store the EL1 Physical Timer's IRQ number in struct arch_timer_kvm_info on VHE systems to allow KVM to use it. Acked-by: Daniel Lezcano Signed-off-by: Andre Przywara Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

arm64: use WFE for long delays

2017-10-13T17:56:15+00:00

The current delay implementation uses the yield instruction, which is a hint that it is beneficial to schedule another thread. As this is a hint, it may be implemented as a NOP, causing all delays to be busy loops. This is the case for many existing CPUs. Taking advantage of the generic timer sending periodic events to all cores, we can use WFE during delays to reduce power consumption. This is beneficial only for delays longer than the period of the timer event stream. If timer event stream is not enabled, delays will behave as yield/busy loops. Signed-off-by: Julien Thierry Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Signed-off-by: Will Deacon

arm_arch_timer: Expose event stream status

2017-10-13T17:55:05+00:00

The arch timer configuration for a CPU might get reset after suspending said CPU. In order to reliably use the event stream in the kernel (e.g. for delays), we keep track of the state where we can safely consider the event stream as properly configured. After writing to cntkctl, we issue an ISB to ensure that subsequent delay loops can rely on the event stream being enabled. Signed-off-by: Julien Thierry Acked-by: Mark Rutland Cc: Marc Zyngier Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Will Deacon

clocksource: arm_arch_timer: add structs to describe MMIO timer

2017-04-19T15:11:48+00:00

In preparation for ACPI GTDT support, this patch adds structs to describe the MMIO timers indepedent of the firmware interface. Subsequent patches will use these to split the FW/HW probing logic, so that the HW probing logic can be shared by ACPI and DT. Signed-off-by: Fu Wei Reviewed-by: Hanjun Guo Signed-off-by: Mark Rutland