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2021-06-22clocksource: Limit number of CPUs checked for clock synchronizationPaul E. McKenney
Currently, if skew is detected on a clock marked CLOCK_SOURCE_VERIFY_PERCPU, that clock is checked on all CPUs. This is thorough, but might not be what you want on a system with a few tens of CPUs, let alone a few hundred of them. Therefore, by default check only up to eight randomly chosen CPUs. Also provide a new clocksource.verify_n_cpus kernel boot parameter. A value of -1 says to check all of the CPUs, and a non-negative value says to randomly select that number of CPUs, without concern about selecting the same CPU multiple times. However, make use of a cpumask so that a given CPU will be checked at most once. Suggested-by: Thomas Gleixner <tglx@linutronix.de> # For verify_n_cpus=1. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Feng Tang <feng.tang@intel.com> Link: https://lore.kernel.org/r/20210527190124.440372-3-paulmck@kernel.org
2021-06-22clocksource: Check per-CPU clock synchronization when marked unstablePaul E. McKenney
Some sorts of per-CPU clock sources have a history of going out of synchronization with each other. However, this problem has purportedy been solved in the past ten years. Except that it is all too possible that the problem has instead simply been made less likely, which might mean that some of the occasional "Marking clocksource 'tsc' as unstable" messages might be due to desynchronization. How would anyone know? Therefore apply CPU-to-CPU synchronization checking to newly unstable clocksource that are marked with the new CLOCK_SOURCE_VERIFY_PERCPU flag. Lists of desynchronized CPUs are printed, with the caveat that if it is the reporting CPU that is itself desynchronized, it will appear that all the other clocks are wrong. Just like in real life. Reported-by: Chris Mason <clm@fb.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Feng Tang <feng.tang@intel.com> Link: https://lore.kernel.org/r/20210527190124.440372-2-paulmck@kernel.org
2021-06-22clocksource: Retry clock read if long delays detectedPaul E. McKenney
When the clocksource watchdog marks a clock as unstable, this might be due to that clock being unstable or it might be due to delays that happen to occur between the reads of the two clocks. Yes, interrupts are disabled across those two reads, but there are no shortage of things that can delay interrupts-disabled regions of code ranging from SMI handlers to vCPU preemption. It would be good to have some indication as to why the clock was marked unstable. Therefore, re-read the watchdog clock on either side of the read from the clock under test. If the watchdog clock shows an excessive time delta between its pair of reads, the reads are retried. The maximum number of retries is specified by a new kernel boot parameter clocksource.max_cswd_read_retries, which defaults to three, that is, up to four reads, one initial and up to three retries. If more than one retry was required, a message is printed on the console (the occasional single retry is expected behavior, especially in guest OSes). If the maximum number of retries is exceeded, the clock under test will be marked unstable. However, the probability of this happening due to various sorts of delays is quite small. In addition, the reason (clock-read delays) for the unstable marking will be apparent. Reported-by: Chris Mason <clm@fb.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Feng Tang <feng.tang@intel.com> Link: https://lore.kernel.org/r/20210527190124.440372-1-paulmck@kernel.org
2021-06-22clockevents: Add missing parameter documentationBaokun Li
Add the missing documentation for the @cpu parameter of tick_cleanup_dead_cpu(). Signed-off-by: Baokun Li <libaokun1@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210608024305.2750999-1-libaokun1@huawei.com
2021-06-18sched,timer: Use __set_current_state()Peter Zijlstra
There's an existing helper for setting TASK_RUNNING; must've gotten lost last time we did this cleanup. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210611082838.409696194@infradead.org
2021-05-31timer_list: Print name of per-cpu wakeup deviceWill Deacon
With the introduction of per-cpu wakeup devices that can be used in preference to the broadcast timer, print the name of such devices when they are available. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210524221818.15850-6-will@kernel.org
2021-05-31tick/broadcast: Program wakeup timer when entering idle if requiredWill Deacon
When configuring the broadcast timer on entry to and exit from deep idle states, prefer a per-CPU wakeup timer if one exists. On entry to idle, stop the tick device and transfer the next event into the oneshot wakeup device, which will serve as the wakeup from idle. To avoid the overhead of additional hardware accesses on exit from idle, leave the timer armed and treat the inevitable interrupt as a (possibly spurious) tick event. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210524221818.15850-5-will@kernel.org
2021-05-31tick/broadcast: Prefer per-cpu oneshot wakeup timers to broadcastWill Deacon
Some SoCs have two per-cpu timer implementations where the timer with the higher rating stops in deep idle (i.e. suffers from CLOCK_EVT_FEAT_C3STOP) but is otherwise preferable to the timer with the lower rating. In such a design, selecting the higher rated devices relies on a global broadcast timer and IPIs to wake up from deep idle states. To avoid the reliance on a global broadcast timer and also to reduce the overhead associated with the IPI wakeups, extend tick_install_broadcast_device() to manage per-cpu wakeup timers separately from the broadcast device. For now, these timers remain unused. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210524221818.15850-4-will@kernel.org
2021-05-31tick/broadcast: Split __tick_broadcast_oneshot_control() into a helperWill Deacon
In preparation for adding support for per-cpu wakeup timers, split _tick_broadcast_oneshot_control() into a helper function which deals only with the broadcast timer management across idle transitions. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210524221818.15850-3-will@kernel.org
2021-05-31tick/broadcast: Drop unneeded CONFIG_GENERIC_CLOCKEVENTS_BROADCAST guardWill Deacon
tick-broadcast.o is only built if CONFIG_GENERIC_CLOCKEVENTS_BROADCAST=y so remove the redundant #ifdef guards around the definition of tick_receive_broadcast(). Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210524221818.15850-2-will@kernel.org
2021-05-31clockevents: Use DEVICE_ATTR_[RO|WO] macrosYueHaibing
Use the DEVICE_ATTR_[RO|WO] helpers instead of plain DEVICE_ATTR, which makes the code a bit shorter and easier to read. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210523065825.19684-1-yuehaibing@huawei.com
2021-05-31tick/nohz: Only check for RCU deferred wakeup on user/guest entry when neededFrederic Weisbecker
Checking for and processing RCU-nocb deferred wakeup upon user/guest entry is only relevant when nohz_full runs on the local CPU, otherwise the periodic tick should take care of it. Make sure we don't needlessly pollute these fast-paths as a -3% performance regression on a will-it-scale.per_process_ops has been reported so far. Fixes: 47b8ff194c1f (entry: Explicitly flush pending rcuog wakeup before last rescheduling point) Fixes: 4ae7dc97f726 (entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point) Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210527113441.465489-1-frederic@kernel.org
2021-05-13tick/nohz: Call tick_nohz_task_switch() with interrupts disabledPeter Zijlstra
Call tick_nohz_task_switch() slightly earlier after the context switch to benefit from disabled IRQs. This way the function doesn't need to disable them once more. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210512232924.150322-10-frederic@kernel.org
2021-05-13tick/nohz: Kick only _queued_ task whose tick dependency is updatedMarcelo Tosatti
When the tick dependency of a task is updated, we want it to aknowledge the new state and restart the tick if needed. If the task is not running, we don't need to kick it because it will observe the new dependency upon scheduling in. But if the task is running, we may need to send an IPI to it so that it gets notified. Unfortunately we don't have the means to check if a task is running in a race free way. Checking p->on_cpu in a synchronized way against p->tick_dep_mask would imply adding a full barrier between prepare_task_switch() and tick_nohz_task_switch(), which we want to avoid in this fast-path. Therefore we blindly fire an IPI to the task's CPU. Meanwhile we can check if the task is queued on the CPU rq because p->on_rq is always set to TASK_ON_RQ_QUEUED _before_ schedule() and its full barrier that precedes tick_nohz_task_switch(). And if the task is queued on a nohz_full CPU, it also has fair chances to be running as the isolation constraints prescribe running single tasks on full dynticks CPUs. So use this as a trick to check if we can spare an IPI toward a non-running task. NOTE: For the ordering to be correct, it is assumed that we never deactivate a task while it is running, the only exception being the task deactivating itself while scheduling out. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512232924.150322-9-frederic@kernel.org
2021-05-13tick/nohz: Change signal tick dependency to wake up CPUs of member tasksMarcelo Tosatti
Rather than waking up all nohz_full CPUs on the system, only wake up the target CPUs of member threads of the signal. Reduces interruptions to nohz_full CPUs. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512232924.150322-8-frederic@kernel.org
2021-05-13tick/nohz: Only wake up a single target cpu when kicking a taskFrederic Weisbecker
When adding a tick dependency to a task, its necessary to wake up the CPU where the task resides to reevaluate tick dependencies on that CPU. However the current code wakes up all nohz_full CPUs, which is unnecessary. Switch to waking up a single CPU, by using ordering of writes to task->cpu and task->tick_dep_mask. [ mingo: Minor readability edit. ] Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512232924.150322-7-frederic@kernel.org
2021-05-13tick/nohz: Update nohz_full Kconfig helpFrederic Weisbecker
CONFIG_NO_HZ_FULL behaves just like CONFIG_NO_HZ_IDLE by default. Reassure distros about it. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512232924.150322-6-frederic@kernel.org
2021-05-13tick/nohz: Update idle_exittime on actual idle exitYunfeng Ye
The idle_exittime field of tick_sched is used to record the time when the idle state was left. but currently the idle_exittime is updated in the function tick_nohz_restart_sched_tick(), which is not always in idle state when nohz_full is configured: tick_irq_exit tick_nohz_irq_exit tick_nohz_full_update_tick tick_nohz_restart_sched_tick ts->idle_exittime = now; It's thus overwritten by mistake on nohz_full tick restart. Move the update to the appropriate idle exit path instead. Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512232924.150322-5-frederic@kernel.org
2021-05-13tick/nohz: Remove superflous check for CONFIG_VIRT_CPU_ACCOUNTING_NATIVEFrederic Weisbecker
The vtime_accounting_enabled_this_cpu() early check already makes what follows as dead code in the case of CONFIG_VIRT_CPU_ACCOUNTING_NATIVE. No need to keep the ifdeferry around. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512232924.150322-4-frederic@kernel.org
2021-05-13tick/nohz: Conditionally restart tick on idle exitYunfeng Ye
In nohz_full mode, switching from idle to a task will unconditionally issue a tick restart. If the task is alone in the runqueue or is the highest priority, the tick will fire once then eventually stop. But that alone is still undesired noise. Therefore, only restart the tick on idle exit when it's strictly necessary. Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512232924.150322-3-frederic@kernel.org
2021-05-11alarmtimer: Check RTC features instead of opsAlexandre Belloni
RTC drivers used to leave .set_alarm() NULL in order to signal the RTC device doesn't support alarms. The drivers are now clearing the RTC_FEATURE_ALARM bit for that purpose in order to keep the rtc_class_ops structure const. So now, .set_alarm() is set unconditionally and this possibly causes the alarmtimer code to select an RTC device that doesn't support alarms. Test RTC_FEATURE_ALARM instead of relying on ops->set_alarm to determine whether alarms are available. Fixes: 7ae41220ef58 ("rtc: introduce features bitfield") Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210511014516.563031-1-alexandre.belloni@bootlin.com
2021-05-10timer: Revert "timer: Add timer_curr_running()"Frederic Weisbecker
This reverts commit dcd42591ebb8a25895b551a5297ea9c24414ba54. The only user was RCU/nocb. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-05-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...
2021-04-26Merge tag 'pm-5.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These add some new hardware support (for example, IceLake-D idle states in intel_idle), fix some issues (for example, the handling of negative "sleep length" values in cpuidle governors), add new functionality to the existing drivers (for example, scale-invariance support in the ACPI CPPC cpufreq driver) and clean up code all over. Specifics: - Add idle states table for IceLake-D to the intel_idle driver and update IceLake-X C6 data in it (Artem Bityutskiy). - Fix the C7 idle state on Tegra114 in the tegra cpuidle driver and drop the unused do_idle() firmware call from it (Dmitry Osipenko). - Fix cpuidle-qcom-spm Kconfig entry (He Ying). - Fix handling of possible negative tick_nohz_get_next_hrtimer() return values of in cpuidle governors (Rafael Wysocki). - Add support for frequency-invariance to the ACPI CPPC cpufreq driver and update the frequency-invariance engine (FIE) to use it as needed (Viresh Kumar). - Simplify the default delay_us setting in the ACPI CPPC cpufreq driver (Tom Saeger). - Clean up frequency-related computations in the intel_pstate cpufreq driver (Rafael Wysocki). - Fix TBG parent setting for load levels in the armada-37xx cpufreq driver and drop the CPU PM clock .set_parent method for armada-37xx (Marek Behún). - Fix multiple issues in the armada-37xx cpufreq driver (Pali Rohár). - Fix handling of dev_pm_opp_of_cpumask_add_table() return values in cpufreq-dt to take the -EPROBE_DEFER one into acconut as appropriate (Quanyang Wang). - Fix format string in ia64-acpi-cpufreq (Sergei Trofimovich). - Drop the unused for_each_policy() macro from cpufreq (Shaokun Zhang). - Simplify computations in the schedutil cpufreq governor to avoid unnecessary overhead (Yue Hu). - Fix typos in the s5pv210 cpufreq driver (Bhaskar Chowdhury). - Fix cpufreq documentation links in Kconfig (Alexander Monakov). - Fix PCI device power state handling in pci_enable_device_flags() to avoid issuse in some cases when the device depends on an ACPI power resource (Rafael Wysocki). - Add missing documentation of pm_runtime_resume_and_get() (Alan Stern). - Add missing static inline stub for pm_runtime_has_no_callbacks() to pm_runtime.h and drop the unused try_to_freeze_nowarn() definition (YueHaibing). - Drop duplicate struct device declaration from pm.h and fix a structure type declaration in intel_rapl.h (Wan Jiabing). - Use dev_set_name() instead of an open-coded equivalent of it in the wakeup sources code and drop a redundant local variable initialization from it (Andy Shevchenko, Colin Ian King). - Use crc32 instead of md5 for e820 memory map integrity check during resume from hibernation on x86 (Chris von Recklinghausen). - Fix typos in comments in the system-wide and hibernation support code (Lu Jialin). - Modify the generic power domains (genpd) code to avoid resuming devices in the "prepare" phase of system-wide suspend and hibernation (Ulf Hansson). - Add Hygon Fam18h RAPL support to the intel_rapl power capping driver (Pu Wen). - Add MAINTAINERS entry for the dynamic thermal power management (DTPM) code (Daniel Lezcano). - Add devm variants of operating performance points (OPP) API functions and switch over some users of the OPP framework to the new resource-managed API (Yangtao Li and Dmitry Osipenko). - Update devfreq core: * Register devfreq devices as cooling devices on demand (Daniel Lezcano). * Add missing unlock opeation in devfreq_add_device() (Lukasz Luba). * Use the next frequency as resume_freq instead of the previous frequency when using the opp-suspend property (Dong Aisheng). * Check get_dev_status in devfreq_update_stats() (Dong Aisheng). * Fix set_freq path for the userspace governor in Kconfig (Dong Aisheng). * Remove invalid description of get_target_freq() (Dong Aisheng). - Update devfreq drivers: * imx8m-ddrc: Remove imx8m_ddrc_get_dev_status() and unneeded of_match_ptr() (Dong Aisheng, Fabio Estevam). * rk3399_dmc: dt-bindings: Add rockchip,pmu phandle and drop references to undefined symbols (Enric Balletbo i Serra, Gaël PORTAY). * rk3399_dmc: Use dev_err_probe() to simplify the code (Krzysztof Kozlowski). * imx-bus: Remove unneeded of_match_ptr() (Fabio Estevam). - Fix kernel-doc warnings in three places (Pierre-Louis Bossart). - Fix typo in the pm-graph utility code (Ricardo Ribalda)" * tag 'pm-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits) PM: wakeup: remove redundant assignment to variable retval PM: hibernate: x86: Use crc32 instead of md5 for hibernation e820 integrity check cpufreq: Kconfig: fix documentation links PM: wakeup: use dev_set_name() directly PM: runtime: Add documentation for pm_runtime_resume_and_get() cpufreq: intel_pstate: Simplify intel_pstate_update_perf_limits() cpufreq: armada-37xx: Fix module unloading cpufreq: armada-37xx: Remove cur_frequency variable cpufreq: armada-37xx: Fix determining base CPU frequency cpufreq: armada-37xx: Fix driver cleanup when registration failed clk: mvebu: armada-37xx-periph: Fix workaround for switching from L1 to L0 clk: mvebu: armada-37xx-periph: Fix switching CPU freq from 250 Mhz to 1 GHz cpufreq: armada-37xx: Fix the AVS value for load L1 clk: mvebu: armada-37xx-periph: remove .set_parent method for CPU PM clock cpufreq: armada-37xx: Fix setting TBG parent for load levels cpuidle: Fix ARM_QCOM_SPM_CPUIDLE configuration cpuidle: tegra: Remove do_idle firmware call cpuidle: tegra: Fix C7 idling state on Tegra114 PM: sleep: fix typos in comments cpufreq: Remove unused for_each_policy macro ...
2021-04-26Merge tag 'timers-core-2021-04-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "The time and timers updates contain: Core changes: - Allow runtime power management when the clocksource is changed. - A correctness fix for clock_adjtime32() so that the return value on success is not overwritten by the result of the copy to user. - Allow late installment of broadcast clockevent devices which was broken because nothing switched them over to oneshot mode. This went unnoticed so far because clockevent devices used to be built in, but now people started to make them modular. - Debugfs related simplifications - Small cleanups and improvements here and there Driver changes: - The usual set of device tree binding updates for a wide range of drivers/devices. - The usual updates and improvements for drivers all over the place but nothing outstanding. - No new clocksource/event drivers. They'll come back next time" * tag 'timers-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) posix-timers: Preserve return value in clock_adjtime32() tick/broadcast: Allow late registered device to enter oneshot mode tick: Use tick_check_replacement() instead of open coding it time/timecounter: Mark 1st argument of timecounter_cyc2time() as const dt-bindings: timer: nuvoton,npcm7xx: Add wpcm450-timer clocksource/drivers/arm_arch_timer: Add __ro_after_init and __init clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940 clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue clocksource/drivers/dw_apb_timer_of: Add handling for potential memory leak clocksource/drivers/npcm: Add support for WPCM450 clocksource/drivers/sh_cmt: Don't use CMTOUT_IE with R-Car Gen2/3 clocksource/drivers/pistachio: Fix trivial typo clocksource/drivers/ingenic_ost: Fix return value check in ingenic_ost_probe() clocksource/drivers/timer-ti-dm: Add missing set_state_oneshot_stopped clocksource/drivers/timer-ti-dm: Fix posted mode status check order dt-bindings: timer: renesas,cmt: Document R8A77961 dt-bindings: timer: renesas,cmt: Add r8a779a0 CMT support clocksource/drivers/ingenic-ost: Add support for the JZ4760B clocksource/drivers/ingenic: Add support for the JZ4760 dt-bindings: timer: ingenic: Add compatible strings for JZ4760(B) ...
2021-04-26Merge tag 'irq-core-2021-04-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The usual updates from the irq departement: Core changes: - Provide IRQF_NO_AUTOEN as a flag for request*_irq() so drivers can be cleaned up which either use a seperate mechanism to prevent auto-enable at request time or have a racy mechanism which disables the interrupt right after request. - Get rid of the last usage of irq_create_identity_mapping() and remove the interface. - An overhaul of tasklet_disable(). Most usage sites of tasklet_disable() are in task context and usually in cleanup, teardown code pathes. tasklet_disable() spinwaits for a tasklet which is currently executed. That's not only a problem for PREEMPT_RT where this can lead to a live lock when the disabling task preempts the softirq thread. It's also problematic in context of virtualization when the vCPU which runs the tasklet is scheduled out and the disabling code has to spin wait until it's scheduled back in. There are a few code pathes which invoke tasklet_disable() from non-sleepable context. For these a new disable variant which still spinwaits is provided which allows to switch tasklet_disable() to a sleep wait mechanism. For the atomic use cases this does not solve the live lock issue on PREEMPT_RT. That is mitigated by blocking on the RT specific softirq lock. - The PREEMPT_RT specific implementation of softirq processing and local_bh_disable/enable(). On RT enabled kernels soft interrupt processing happens always in task context and all interrupt handlers, which are not explicitly marked to be invoked in hard interrupt context are forced into task context as well. This allows to protect against softirq processing with a per CPU lock, which in turn allows to make BH disabled regions preemptible. Most of the softirq handling code is still shared. The RT/non-RT specific differences are addressed with a set of inline functions which provide the context specific functionality. The local_bh_disable() / local_bh_enable() mechanism are obviously seperate. - The usual set of small improvements and cleanups Driver changes: - New drivers for Nuvoton WPCM450 and DT 79rc3243x interrupt controllers - Extended functionality for MStar, STM32 and SC7280 irq chips - Enhanced robustness for ARM GICv3/4.1 drivers - The usual set of cleanups and improvements all over the place" * tag 'irq-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) irqchip/xilinx: Expose Kconfig option for Zynq/ZynqMP irqchip/gic-v3: Do not enable irqs when handling spurious interrups dt-bindings: interrupt-controller: Add IDT 79RC3243x Interrupt Controller irqchip: Add support for IDT 79rc3243x interrupt controller irqdomain: Drop references to recusive irqdomain setup irqdomain: Get rid of irq_create_strict_mappings() irqchip/jcore-aic: Kill use of irq_create_strict_mappings() ARM: PXA: Kill use of irq_create_strict_mappings() irqchip/gic-v4.1: Disable vSGI upon (GIC CPUIF < v4.1) detection irqchip/tb10x: Use 'fallthrough' to eliminate a warning genirq: Reduce irqdebug cacheline bouncing kernel: Initialize cpumask before parsing irqchip/wpcm450: Drop COMPILE_TEST irqchip/irq-mst: Support polarity configuration irqchip: Add driver for WPCM450 interrupt controller dt-bindings: interrupt-controller: Add nuvoton, wpcm450-aic dt-bindings: qcom,pdc: Add compatible for sc7280 irqchip/stm32: Add usart instances exti direct event support irqchip/gic-v3: Fix OF_BAD_ADDR error handling irqchip/sifive-plic: Mark two global variables __ro_after_init ...
2021-04-23Merge tag 'kvmarm-5.13' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 5.13 New features: - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler - Alexandru is now a reviewer (not really a new feature...) Fixes: - Proper emulation of the GICR_TYPER register - Handle the complete set of relocation in the nVHE EL2 object - Get rid of the oprofile dependency in the PMU code (and of the oprofile body parts at the same time) - Debug and SPE fixes - Fix vcpu reset
2021-04-17posix-timers: Preserve return value in clock_adjtime32()Chen Jun
The return value on success (>= 0) is overwritten by the return value of put_old_timex32(). That works correct in the fault case, but is wrong for the success case where put_old_timex32() returns 0. Just check the return value of put_old_timex32() and return -EFAULT in case it is not zero. [ tglx: Massage changelog ] Fixes: 3a4d44b61625 ("ntp: Move adjtimex related compat syscalls to native counterparts") Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Cochran <richardcochran@gmail.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210414030449.90692-1-chenjun102@huawei.com
2021-04-16tick/broadcast: Allow late registered device to enter oneshot modeJindong Yue
The broadcast device is switched to oneshot mode when the system switches to oneshot mode. If a broadcast clock event device is registered after the system switched to oneshot mode, it will stay in periodic mode forever. Ensure that a late registered device which is selected as broadcast device is initialized in oneshot mode when the system already uses oneshot mode. [ tglx: Massage changelog ] Signed-off-by: Jindong Yue <jindong.yue@nxp.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210331083318.21794-1-jindong.yue@nxp.com
2021-04-16tick: Use tick_check_replacement() instead of open coding itWang Wensheng
The function tick_check_replacement() is the combination of tick_check_percpu() and tick_check_preferred(), but tick_check_new_device() has the same logic open coded. Use the helper to simplify the code. [ tglx: Massage changelog ] Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210326022328.3266-1-wangwensheng4@huawei.com
2021-04-16time/timecounter: Mark 1st argument of timecounter_cyc2time() as constMarc Kleine-Budde
The timecounter is not modified in this function. Mark it as const. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210303103544.994855-1-mkl@pengutronix.de
2021-04-08Merge back earlier cpuidle updates for v5.13.Rafael J. Wysocki
2021-04-07tick/nohz: Improve tick_nohz_get_next_hrtimer() kerneldocRafael J. Wysocki
Make the tick_nohz_get_next_hrtimer() kerneldoc comment state clearly that the function may return negative numbers. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-04-07time: Add mechanism to recognize clocksource in time_get_snapshotThomas Gleixner
System time snapshots are not conveying information about the current clocksource which was used, but callers like the PTP KVM guest implementation have the requirement to evaluate the clocksource type to select the appropriate mechanism. Introduce a clocksource id field in struct clocksource which is by default set to CSID_GENERIC (0). Clocksource implementations can set that field to a value which allows to identify the clocksource. Store the clocksource id of the current clocksource in the system_time_snapshot so callers can evaluate which clocksource was used to take the snapshot and act accordingly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201209060932.212364-5-jianyong.wu@arm.com
2021-03-29timekeeping: Allow runtime PM from change_clocksource()Niklas Söderlund
The struct clocksource callbacks enable() and disable() are described as a way to allow clock sources to enter a power save mode. See commit 4614e6adafa2 ("clocksource: add enable() and disable() callbacks") But using runtime PM from these callbacks triggers a cyclic lockdep warning when switching clock source using change_clocksource(). # echo e60f0000.timer > /sys/devices/system/clocksource/clocksource0/current_clocksource ====================================================== WARNING: possible circular locking dependency detected ------------------------------------------------------ migration/0/11 is trying to acquire lock: ffff0000403ed220 (&dev->power.lock){-...}-{2:2}, at: __pm_runtime_resume+0x40/0x74 but task is already holding lock: ffff8000113c8f88 (tk_core.seq.seqcount){----}-{0:0}, at: multi_cpu_stop+0xa4/0x190 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (tk_core.seq.seqcount){----}-{0:0}: ktime_get+0x28/0xa0 hrtimer_start_range_ns+0x210/0x2dc generic_sched_clock_init+0x70/0x88 sched_clock_init+0x40/0x64 start_kernel+0x494/0x524 -> #1 (hrtimer_bases.lock){-.-.}-{2:2}: hrtimer_start_range_ns+0x68/0x2dc rpm_suspend+0x308/0x5dc rpm_idle+0xc4/0x2a4 pm_runtime_work+0x98/0xc0 process_one_work+0x294/0x6f0 worker_thread+0x70/0x45c kthread+0x154/0x160 ret_from_fork+0x10/0x20 -> #0 (&dev->power.lock){-...}-{2:2}: _raw_spin_lock_irqsave+0x7c/0xc4 __pm_runtime_resume+0x40/0x74 sh_cmt_start+0x1c4/0x260 sh_cmt_clocksource_enable+0x28/0x50 change_clocksource+0x9c/0x160 multi_cpu_stop+0xa4/0x190 cpu_stopper_thread+0x90/0x154 smpboot_thread_fn+0x244/0x270 kthread+0x154/0x160 ret_from_fork+0x10/0x20 other info that might help us debug this: Chain exists of: &dev->power.lock --> hrtimer_bases.lock --> tk_core.seq.seqcount Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tk_core.seq.seqcount); lock(hrtimer_bases.lock); lock(tk_core.seq.seqcount); lock(&dev->power.lock); *** DEADLOCK *** 2 locks held by migration/0/11: #0: ffff8000113c9278 (timekeeper_lock){-.-.}-{2:2}, at: change_clocksource+0x2c/0x160 #1: ffff8000113c8f88 (tk_core.seq.seqcount){----}-{0:0}, at: multi_cpu_stop+0xa4/0x190 Rework change_clocksource() so it enables the new clocksource and disables the old clocksource outside of the timekeeper_lock and seqcount write held region. There is no requirement that these callbacks are invoked from the lock held region. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20210211134318.323910-1-niklas.soderlund+renesas@ragnatech.se
2021-03-22timekeeping, clocksource: Fix various typos in commentsIngo Molnar
Fix ~56 single-word typos in timekeeping & clocksource code comments. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-kernel@vger.kernel.org
2021-03-18time/debug: Remove dentry pointer for debugfsGreg Kroah-Hartman
There is no need to keep the dentry pointer around for the created debugfs file, as it is only needed when removing it from the system. When it is to be removed, ask debugfs itself for the pointer, to save on storage and make things a bit simpler. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210216155020.1012407-1-gregkh@linuxfoundation.org
2021-03-17tick/sched: Prevent false positive softirq pending warnings on RTThomas Gleixner
On RT a task which has soft interrupts disabled can block on a lock and schedule out to idle while soft interrupts are pending. This triggers the warning in the NOHZ idle code which complains about going idle with pending soft interrupts. But as the task is blocked soft interrupt processing is temporarily blocked as well which means that such a warning is a false positive. To prevent that check the per CPU state which indicates that a scheduled out task has soft interrupts disabled. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309085727.527563866@linutronix.de
2021-03-16kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data()Oleg Nesterov
Preparation for fixing get_nr_restart_syscall() on X86 for COMPAT. Add a new helper which sets restart_block->fn and calls a dummy arch_set_restart_data() helper. Fixes: 609c19a385c8 ("x86/ptrace: Stop setting TS_COMPAT in ptrace code") Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210201174641.GA17871@redhat.com
2021-03-08hrtimer: Update softirq_expires_next correctly after __hrtimer_get_next_event()Anna-Maria Behnsen
hrtimer_force_reprogram() and hrtimer_interrupt() invokes __hrtimer_get_next_event() to find the earliest expiry time of hrtimer bases. __hrtimer_get_next_event() does not update cpu_base::[softirq_]_expires_next to preserve reprogramming logic. That needs to be done at the callsites. hrtimer_force_reprogram() updates cpu_base::softirq_expires_next only when the first expiring timer is a softirq timer and the soft interrupt is not activated. That's wrong because cpu_base::softirq_expires_next is left stale when the first expiring timer of all bases is a timer which expires in hard interrupt context. hrtimer_interrupt() does never update cpu_base::softirq_expires_next which is wrong too. That becomes a problem when clock_settime() sets CLOCK_REALTIME forward and the first soft expiring timer is in the CLOCK_REALTIME_SOFT base. Setting CLOCK_REALTIME forward moves the clock MONOTONIC based expiry time of that timer before the stale cpu_base::softirq_expires_next. cpu_base::softirq_expires_next is cached to make the check for raising the soft interrupt fast. In the above case the soft interrupt won't be raised until clock monotonic reaches the stale cpu_base::softirq_expires_next value. That's incorrect, but what's worse it that if the softirq timer becomes the first expiring timer of all clock bases after the hard expiry timer has been handled the reprogramming of the clockevent from hrtimer_interrupt() will result in an interrupt storm. That happens because the reprogramming does not use cpu_base::softirq_expires_next, it uses __hrtimer_get_next_event() which returns the actual expiry time. Once clock MONOTONIC reaches cpu_base::softirq_expires_next the soft interrupt is raised and the storm subsides. Change the logic in hrtimer_force_reprogram() to evaluate the soft and hard bases seperately, update softirq_expires_next and handle the case when a soft expiring timer is the first of all bases by comparing the expiry times and updating the required cpu base fields. Split this functionality into a separate function to be able to use it in hrtimer_interrupt() as well without copy paste. Fixes: 5da70160462e ("hrtimer: Implement support for softirq based hrtimers") Reported-by: Mikael Beckius <mikael.beckius@windriver.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mikael Beckius <mikael.beckius@windriver.com> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210223160240.27518-1-anna-maria@linutronix.de
2021-02-21Merge tag 'core-rcu-2021-02-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "These are the latest RCU updates for v5.12: - Documentation updates. - Miscellaneous fixes. - kfree_rcu() updates: Addition of mem_dump_obj() to provide allocator return addresses to more easily locate bugs. This has a couple of RCU-related commits, but is mostly MM. Was pulled in with akpm's agreement. - Per-callback-batch tracking of numbers of callbacks, which enables better debugging information and smarter reactions to large numbers of callbacks. - The first round of changes to allow CPUs to be runtime switched from and to callback-offloaded state. - CONFIG_PREEMPT_RT-related changes. - RCU CPU stall warning updates. - Addition of polling grace-period APIs for SRCU. - Torture-test and torture-test scripting updates, including a "torture everything" script that runs rcutorture, locktorture, scftorture, rcuscale, and refscale. Plus does an allmodconfig build. - nolibc fixes for the torture tests" * tag 'core-rcu-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (130 commits) percpu_ref: Dump mem_dump_obj() info upon reference-count underflow rcu: Make call_rcu() print mem_dump_obj() info for double-freed callback mm: Make mem_obj_dump() vmalloc() dumps include start and length mm: Make mem_dump_obj() handle vmalloc() memory mm: Make mem_dump_obj() handle NULL and zero-sized pointers mm: Add mem_dump_obj() to print source of memory block tools/rcutorture: Fix position of -lgcc in mkinitrd.sh tools/nolibc: Fix position of -lgcc in the documented example tools/nolibc: Emit detailed error for missing alternate syscall number definitions tools/nolibc: Remove incorrect definitions of __ARCH_WANT_* tools/nolibc: Get timeval, timespec and timezone from linux/time.h tools/nolibc: Implement poll() based on ppoll() tools/nolibc: Implement fork() based on clone() tools/nolibc: Make getpgrp() fall back to getpgid(0) tools/nolibc: Make dup2() rely on dup3() when available tools/nolibc: Add the definition for dup() rcutorture: Add rcutree.use_softirq=0 to RUDE01 and TASKS01 torture: Maintain torture-specific set of CPUs-online books torture: Clean up after torture-test CPU hotplugging rcutorture: Make object_debug also double call_rcu() heap object ...
2021-02-21Merge tag 'timers-core-2021-02-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Time and timer updates: - Instead of new drivers remove tango, sirf, u300 and atlas drivers - Add suspend/resume support for microchip pit64b - The usual fixes, improvements and cleanups here and there" * tag 'timers-core-2021-02-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timens: Delete no-op time_ns_init() alarmtimer: Update kerneldoc clocksource/drivers/timer-microchip-pit64b: Add clocksource suspend/resume clocksource/drivers/prima: Remove sirf prima driver clocksource/drivers/atlas: Remove sirf atlas driver clocksource/drivers/tango: Remove tango driver clocksource/drivers/u300: Remove the u300 driver dt-bindings: timer: nuvoton: Clarify that interrupt of timer 0 should be specified clocksource/drivers/davinci: Move pr_fmt() before the includes clocksource/drivers/efm32: Drop unused timer code
2021-02-12Merge branch 'for-mingo-rcu' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: - Documentation updates. - Miscellaneous fixes. - kfree_rcu() updates: Addition of mem_dump_obj() to provide allocator return addresses to more easily locate bugs. This has a couple of RCU-related commits, but is mostly MM. Was pulled in with akpm's agreement. - Per-callback-batch tracking of numbers of callbacks, which enables better debugging information and smarter reactions to large numbers of callbacks. - The first round of changes to allow CPUs to be runtime switched from and to callback-offloaded state. - CONFIG_PREEMPT_RT-related changes. - RCU CPU stall warning updates. - Addition of polling grace-period APIs for SRCU. - Torture-test and torture-test scripting updates, including a "torture everything" script that runs rcutorture, locktorture, scftorture, rcuscale, and refscale. Plus does an allmodconfig build. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-02-05timens: Delete no-op time_ns_init()Alexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andrei Vagin <avagin@gmail.com> Link: https://lore.kernel.org/r/20201228215402.GA572900@localhost.localdomain
2021-02-05alarmtimer: Update kerneldocAlexandre Belloni
Update kerneldoc comments to reflect the actual arguments and return values of the documented functions. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210202013457.3482388-1-alexandre.belloni@bootlin.com
2021-02-05ntp: Use freezable workqueue for RTC synchronizationGeert Uytterhoeven
The bug fixed by commit e3fab2f3de081e98 ("ntp: Fix RTC synchronization on 32-bit platforms") revealed an underlying issue: RTC synchronization may happen anytime, even while the system is partially suspended. On systems where the RTC is connected to an I2C bus, the I2C bus controller may already or still be suspended, triggering a WARNING during suspend or resume from s2ram: WARNING: CPU: 0 PID: 124 at drivers/i2c/i2c-core.h:54 __i2c_transfer+0x634/0x680 i2c i2c-6: Transfer while suspended [...] Workqueue: events_power_efficient sync_hw_clock [...] (__i2c_transfer) (i2c_transfer) (regmap_i2c_read) ... (da9063_rtc_set_time) (rtc_set_time) (sync_hw_clock) (process_one_work) Fix this race condition by using the freezable instead of the normal power-efficient workqueue. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20210125143039.1051912-1-geert+renesas@glider.be
2021-01-12ntp: Fix RTC synchronization on 32-bit platformsGeert Uytterhoeven
Due to an integer overflow, RTC synchronization now happens every 2s instead of the intended 11 minutes. Fix this by forcing 64-bit arithmetic for the sync period calculation. Annotate the other place which multiplies seconds for consistency as well. Fixes: c9e6189fb03123a7 ("ntp: Make the RTC synchronization more reliable") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210111103956.290378-1-geert+renesas@glider.be
2021-01-12timekeeping: Remove unused get_seconds()Chunguang Xu
The get_seconds() cleanup seems to have been completed, now it is time to delete the legacy interface to avoid misuse later. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/1606816351-26900-1-git-send-email-brookxu@tencent.com
2021-01-06rcu/nocb: Code-style nits in callback-offloading togglingPaul E. McKenney
This commit addresses a few code-style nits in callback-offloading toggling, including one that predates this toggling. Cc: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06timer: Add timer_curr_running()Frederic Weisbecker
This commit adds a timer_curr_running() function that verifies that the current code is running in the context of the specified timer's handler. Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>