kernel/linux.git/drivers/clocksource/arm_arch_timer.c, branch v5.4.113

clocksource/drivers/arm_arch_timer: Correct fault programming of CNTKCTL_EL1.EVNTI

2020-12-30T10:51:19+00:00

[ Upstream commit 8b7770b877d187bfdae1eaf587bd2b792479a31c ] ARM virtual counter supports event stream, it can only trigger an event when the trigger bit (the value of CNTKCTL_EL1.EVNTI) of CNTVCT_EL0 changes, so the actual period of event stream is 2^(cntkctl_evnti + 1). For example, when the trigger bit is 0, then virtual counter trigger an event for every two cycles. While we're at it, rework the way we compute the trigger bit position by making it more obvious that when bits [n:n-1] are both set (with n being the most significant bit), we pick bit (n + 1). Fixes: 037f637767a8 ("drivers: clocksource: add support for ARM architected timer event stream") Suggested-by: Marc Zyngier Signed-off-by: Keqian Zhu Acked-by: Marc Zyngier Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201204073126.6920-3-zhukeqian1@huawei.com Signed-off-by: Sasha Levin

clocksource/drivers/arm_arch_timer: Use stable count reader in erratum sne

2020-12-30T10:51:19+00:00

[ Upstream commit d8cc3905b8073c7cfbff94af889fa8dc71f21dd5 ] In commit 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters"), we separate stable and normal count reader to omit unnecessary overhead on systems that have no timer erratum. However, in erratum_set_next_event_tval_generic(), count reader becomes normal reader. This converts it to stable reader. Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters") Acked-by: Marc Zyngier Signed-off-by: Keqian Zhu Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201204073126.6920-2-zhukeqian1@huawei.com Signed-off-by: Sasha Levin

arm64: arch_timer: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040

2020-07-22T07:32:51+00:00

commit 4b661d6133c5d3a7c9aca0b4ee5a78c7766eff3f upstream. ARM64_WORKAROUND_1418040 requires that AArch32 EL0 accesses to the virtual counter register are trapped and emulated by the kernel. This makes the vdso pretty pointless, and in some cases livelock prone. Provide a workaround entry that limits the vdso to 64bit tasks. Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200706163802.1836732-4-maz@kernel.org Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

arm64: arch_timer: Allow an workaround descriptor to disable compat vdso

2020-07-22T07:32:50+00:00

commit c1fbec4ac0d701f350a581941d35643d5a9cd184 upstream. As we are about to disable the vdso for compat tasks in some circumstances, let's allow a workaround descriptor to express exactly that. Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200706163802.1836732-3-maz@kernel.org Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

arm64: Introduce a way to disable the 32bit vdso

2020-07-22T07:32:50+00:00

commit 97884ca8c2925d14c32188e865069f21378b4b4f upstream. [this is a redesign rather than a backport] We have a class of errata (grouped under the ARM64_WORKAROUND_1418040 banner) that force the trapping of counter access from 32bit EL0. We would normally disable the whole vdso for such defect, except that it would disable it for 64bit userspace as well, which is a shame. Instead, add a new vdso_clock_mode, which signals that the vdso isn't usable for compat tasks. This gets checked in the new vdso_clocksource_ok() helper, now provided for the 32bit vdso. Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200706163802.1836732-2-maz@kernel.org Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

Merge branch 'timers/vdso' into timers/core

2019-07-03T08:50:21+00:00

so the hyper-v clocksource update can be applied.

clocksource/drivers/arm_arch_timer: Extract elf_hwcap use to arch-helper

2019-06-25T17:49:18+00:00

Different mechanisms are used to test and set elf_hwcaps between ARM and ARM64, this results in the use of ifdeferry in this file when setting/testing for the EVTSTRM hwcap. Let's improve readability by extracting this to an arch helper. Signed-off-by: Andrew Murray Acked-by: Mark Rutland Acked-by: Will Deacon Signed-off-by: Daniel Lezcano

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/arm_arch_timer: Don't trace count reader functions

2019-06-12T13:38:54+00:00

With v5.2-rc1, The ftrace functions_graph tracer locks up whenever it is enabled on arm64. Since commit 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters") a function pointer is consistently used to read the counter instead of potentially referencing an inlinable function. The graph tracers relies on accessing the timer counters to compute the time spent in functions which causes the lockup when attempting to trace these code paths. Annotate the arm arch timer counter accessors as notrace. Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters") Signed-off-by: Julien Thierry Cc: Marc Zyngier Cc: Mark Rutland Cc: Daniel Lezcano Cc: Thomas Gleixner Cc: Steven Rostedt Acked-by: Marc Zyngier Signed-off-by: Daniel Lezcano

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2019-05-07T00:54:22+00:00

Pull arm64 updates from Will Deacon: "Mostly just incremental improvements here: - Introduce AT_HWCAP2 for advertising CPU features to userspace - Expose SVE2 availability to userspace - Support for "data cache clean to point of deep persistence" (DC PODP) - Honour "mitigations=off" on the cmdline and advertise status via sysfs - CPU timer erratum workaround (Neoverse-N1 #1188873) - Introduce perf PMU driver for the SMMUv3 performance counters - Add config option to disable the kuser helpers page for AArch32 tasks - Futex modifications to ensure liveness under contention - Rework debug exception handling to seperate kernel and user handlers - Non-critical fixes and cleanup" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits) Documentation: Add ARM64 to kernel-parameters.rst arm64/speculation: Support 'mitigations=' cmdline option arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB arm64: enable generic CPU vulnerabilites support arm64: add sysfs vulnerability show for speculative store bypass arm64: Fix size of __early_cpu_boot_status clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters clocksource/arm_arch_timer: Remove use of workaround static key clocksource/arm_arch_timer: Drop use of static key in arch_timer_reg_read_stable clocksource/arm_arch_timer: Direcly assign set_next_event workaround arm64: Use arch_timer_read_counter instead of arch_counter_get_cntvct watchdog/sbsa: Use arch_timer_read_counter instead of arch_counter_get_cntvct ARM: vdso: Remove dependency with the arch_timer driver internals arm64: Apply ARM64_ERRATUM_1188873 to Neoverse-N1 arm64: Add part number for Neoverse N1 arm64: Make ARM64_ERRATUM_1188873 depend on COMPAT arm64: Restrict ARM64_ERRATUM_1188873 mitigation to AArch32 arm64: mm: Remove pte_unmap_nested() arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable arm64: compat: Reduce address limit for 64K pages ...