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path: root/include/clocksource/arm_arch_timer.h
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2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner
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 <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19clocksource/arm_arch_timer: Store physical timer IRQ number for KVM on VHEAndre Przywara
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 <daniel.lezcano@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2017-10-13arm64: use WFE for long delaysJulien Thierry
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 <julien.thierry@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-13arm_arch_timer: Expose event stream statusJulien Thierry
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 <julien.thierry@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-04-19clocksource: arm_arch_timer: add structs to describe MMIO timerFu Wei
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 <fu.wei@linaro.org> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> 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>
2016-05-03clocksource: arm_arch_timer: Remove arch_timer_get_timecounterJulien Grall
The only call of arch_timer_get_timecounter (in KVM) has been removed. Signed-off-by: Julien Grall <julien.grall@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-03clocksource: arm_arch_timer: Extend arch_timer_kvm_info to get the virtual IRQJulien Grall
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 <julien.grall@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-03clocksource: arm_arch_timer: Gather KVM specific information in a structureJulien Grall
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 <julien.grall@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14arm64: KVM: Implement timer save/restoreMarc Zyngier
Implement the timer save restore as a direct translation of the assembly code version. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-12-30time: move the timecounter/cyclecounter code into its own file.Richard Cochran
The timecounter code has almost nothing to do with the clocksource code. Let it live in its own file. This will help isolate the timecounter users from the clocksource users in the source tree. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-26drivers: clocksource: add support for ARM architected timer event streamWill Deacon
The ARM architected timer can generate events (used for waking up CPUs executing the wfe instruction) at a frequency represented as a power-of-2 divisor of the clock rate. An event stream might be used: - To implement wfe-based timeouts for userspace locking implementations. - To impose a timeout on a wfe for safeguarding against any programming error in case an expected event is not generated. This patch computes the event stream frequency aiming for a period of 100us between events. It uses ARM/ARM64 specific backends to configure and enable the event stream. Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Will Deacon <will.deacon@arm.com> [sudeep: moving ARM/ARM64 changes into separate patches and adding Kconfig option] Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
2013-09-26ARM/ARM64: arch_timer: add macros for bits in control registerSudeep KarkadaNagesha
Add macros to describe the bitfields in the ARM architected timer control register to make code easy to understand. Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
2013-08-01clocksource: arch_timer: Add support for memory mapped timersStephen Boyd
Add support for the memory mapped timers by filling in the read/write functions and adding some parsing code. Note that we only register one clocksource, preferring the cp15 based clocksource over the mmio one. To keep things simple we register one global clockevent. This covers the case of UP and SMP systems with only mmio hardware and systems where the memory mapped timers are used as the broadcast timer in low power modes. The DT binding allows for per-CPU memory mapped timers in case we want to support that in the future, but the code isn't added here. We also don't do much for hypervisor support, although it should be possible to support it by searching for at least two frames where one frame has the virtual capability and then updating KVM timers to support it. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <Marc.Zyngier@arm.com> Cc: Rob Herring <robherring2@gmail.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com>
2013-08-01clocksource: arch_timer: Make register accessors less error-proneStephen Boyd
Using an enum for the register we wish to access allows newer compilers to determine if we've forgotten a case in our switch statement. This allows us to remove the BUILD_BUG() instances in the arm64 port, avoiding problems where optimizations may not happen. To try and force better code generation we're currently marking the accessor functions as inline, but newer compilers can ignore the inline keyword unless it's marked __always_inline. Luckily on arm and arm64 inline is __always_inline, but let's make everything __always_inline to be explicit. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <Marc.Zyngier@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com>
2013-06-07clocksource: arch_timer: use virtual countersMark Rutland
Switching between reading the virtual or physical counters is problematic, as some core code wants a view of time before we're fully set up. Using a function pointer and switching the source after the first read can make time appear to go backwards, and having a check in the read function is an unfortunate block on what we want to be a fast path. Instead, this patch makes us always use the virtual counters. If we're a guest, or don't have hyp mode, we'll use the virtual timers, and as such don't care about CNTVOFF as long as it doesn't change in such a way as to make time appear to travel backwards. As the guest will use the virtual timers, a (potential) KVM host must use the physical timers (which can wake up the host even if they fire while a guest is executing), and hence a host must have CNTVOFF set to zero so as to have a consistent view of time between the physical timers and virtual counters. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Rob Herring <rob.herring@calxeda.com>
2013-04-11ARM: convert arm/arm64 arch timer to use CLKSRC_OF initRob Herring
This converts arm and arm64 to use CLKSRC_OF DT based initialization for the arch timer. A new function arch_timer_arch_init is added to allow for arch specific setup. This has a side effect of enabling sched_clock on omap5 and exynos5. There should not be any reason not to use the arch timers for sched_clock. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Simon Horman <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-samsung-soc@vger.kernel.org Cc: linux-omap@vger.kernel.org Cc: linux-sh@vger.kernel.org Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
2013-02-11arm: arch_timer: add missing inline in stub functionOlof Johansson
Fixes: In file included from arch/arm/include/asm/arch_timer.h:10:0, from arch/arm/mach-shmobile/timer.c:23: include/clocksource/arm_arch_timer.h:56:28: warning: 'arch_timer_get_timecounter' defined but not used [-Wunused-function] Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-31arm: arch_timer: move core to drivers/clocksourceMark Rutland
The core functionality of the arch_timer driver is not directly tied to anything under arch/arm, and can be split out. This patch factors out the core of the arch_timer driver, so it can be shared with other architectures. A couple of functions are added so that architecture-specific code can interact with the driver without needing to touch its internals. The ARM_ARCH_TIMER config variable is moved out to drivers/clocksource/Kconfig, existing uses in arch/arm are replaced with HAVE_ARM_ARCH_TIMER, which selects it. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com>