user/sven/linux.git/kernel/irq, branch v5.18.13

genirq: Remove WARN_ON_ONCE() in generic_handle_domain_irq()

2022-05-11T00:22:52Z

Since commit 0953fb263714 ("irq: remove handle_domain_{irq,nmi}()"), generic_handle_domain_irq() warns if called outside hardirq context, even though the function calls down to handle_irq_desc(), which warns about the same, but conditionally on handle_enforce_irqctx(). The newly added warning is a false positive if the interrupt originates from any other irqchip than x86 APIC or ARM GIC/GICv3. Those are the only ones for which handle_enforce_irqctx() returns true. Per commit c16816acd086 ("genirq: Add protection against unsafe usage of generic_handle_irq()"): "In general calling generic_handle_irq() with interrupts disabled from non interrupt context is harmless. For some interrupt controllers like the x86 trainwrecks this is outright dangerous as it might corrupt state if an interrupt affinity change is pending." Examples for interrupt chips where the warning is a false positive are USB-attached GPIO controllers such as drivers/gpio/gpio-dln2.c: USB gadgets are incapable of directly signaling an interrupt because they cannot initiate a bus transaction by themselves. All communication on the bus is initiated by the host controller, which polls a gadget's Interrupt Endpoint in regular intervals. If an interrupt is pending, that information is passed up the stack in softirq context, from which a hardirq is synthesized via generic_handle_domain_irq(). Remove the warning to eliminate such false positives. Fixes: 0953fb263714 ("irq: remove handle_domain_{irq,nmi}()") Signed-off-by: Lukas Wunner Signed-off-by: Thomas Gleixner Cc: Marc Zyngier Cc: Mark Rutland Cc: Jakub Kicinski CC: Linus Walleij Cc: Bartosz Golaszewski Cc: Octavian Purdila Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220505113207.487861b2@kernel.org Link: https://lore.kernel.org/r/20220506203242.GA1855@wunner.de Link: https://lore.kernel.org/r/c3caf60bfa78e5fdbdf483096b7174da65d1813a.1652168866.git.lukas@wunner.de

genirq: Synchronize interrupt thread startup

2022-05-05T09:54:05Z

A kernel hang can be observed when running setserial in a loop on a kernel with force threaded interrupts. The sequence of events is: setserial open("/dev/ttyXXX") request_irq() do_stuff() -> serial interrupt -> wake(irq_thread) desc->threads_active++; close() free_irq() kthread_stop(irq_thread) synchronize_irq() <- hangs because desc->threads_active != 0 The thread is created in request_irq() and woken up, but does not get on a CPU to reach the actual thread function, which would handle the pending wake-up. kthread_stop() sets the should stop condition which makes the thread immediately exit, which in turn leaves the stale threads_active count around. This problem was introduced with commit 519cc8652b3a, which addressed a interrupt sharing issue in the PCIe code. Before that commit free_irq() invoked synchronize_irq(), which waits for the hard interrupt handler and also for associated threads to complete. To address the PCIe issue synchronize_irq() was replaced with __synchronize_hardirq(), which only waits for the hard interrupt handler to complete, but not for threaded handlers. This was done under the assumption, that the interrupt thread already reached the thread function and waits for a wake-up, which is guaranteed to be handled before acting on the stop condition. The problematic case, that the thread would not reach the thread function, was obviously overlooked. Make sure that the interrupt thread is really started and reaches thread_fn() before returning from __setup_irq(). This utilizes the existing wait queue in the interrupt descriptor. The wait queue is unused for non-shared interrupts. For shared interrupts the usage might cause a spurious wake-up of a waiter in synchronize_irq() or the completion of a threaded handler might cause a spurious wake-up of the waiter for the ready flag. Both are harmless and have no functional impact. [ tglx: Amended changelog ] Fixes: 519cc8652b3a ("genirq: Synchronize only with single thread on free_irq()") Signed-off-by: Thomas Pfaff Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/552fe7b4-9224-b183-bb87-a8f36d335690@pcs.com

genirq/affinity: Consider that CPUs on nodes can be unbalanced

2022-04-11T07:58:03Z

If CPUs on a node are offline at boot time, the number of nodes is different when building affinity masks for present cpus and when building affinity masks for possible cpus. This causes the following problem: In the case that the number of vectors is less than the number of nodes there are cases where bits of masks for present cpus are overwritten when building masks for possible cpus. Fix this by excluding CPUs, which are not part of the current build mask (present/possible). [ tglx: Massaged changelog and added comment ] Fixes: b82592199032 ("genirq/affinity: Spread IRQs to all available NUMA nodes") Signed-off-by: Rei Yamamoto Signed-off-by: Thomas Gleixner Reviewed-by: Ming Lei Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220331003309.10891-1-yamamoto.rei@jp.fujitsu.com

Merge tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-03-22T21:39:12Z

Pull scheduler updates from Ingo Molnar: - Cleanups for SCHED_DEADLINE - Tracing updates/fixes - CPU Accounting fixes - First wave of changes to optimize the overhead of the scheduler build, from the fast-headers tree - including placeholder *_api.h headers for later header split-ups. - Preempt-dynamic using static_branch() for ARM64 - Isolation housekeeping mask rework; preperatory for further changes - NUMA-balancing: deal with CPU-less nodes - NUMA-balancing: tune systems that have multiple LLC cache domains per node (eg. AMD) - Updates to RSEQ UAPI in preparation for glibc usage - Lots of RSEQ/selftests, for same - Add Suren as PSI co-maintainer * tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits) sched/headers: ARM needs asm/paravirt_api_clock.h too sched/numa: Fix boot crash on arm64 systems headers/prep: Fix header to build standalone: sched/headers: Only include when CONFIG_GENERIC_ENTRY=y cgroup: Fix suspicious rcu_dereference_check() usage warning sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity() sched/deadline,rt: Remove unused functions for !CONFIG_SMP sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistently sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy() sched/deadline: Move bandwidth mgmt and reclaim functions into sched class source file sched/deadline: Remove unused def_dl_bandwidth sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE sched/tracing: Don't re-read p->state when emitting sched_switch event sched/rt: Plug rt_mutex_setprio() vs push_rt_task() race sched/cpuacct: Remove redundant RCU read lock sched/cpuacct: Optimize away RCU read lock sched/cpuacct: Fix charge percpu cpuusage sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies ...

Merge tag 'irqchip-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

2022-03-14T09:23:22Z

Pull irqchip updates from Marc Zyngier: - Add support for the STM32MP13 variant - Move parent device away from struct irq_chip - Remove all instances of non-const strings assigned to struct irq_chip::name, enabling a nice cleanup for VIC and GIC) - Simplify the Qualcomm PDC driver - A bunch of SiFive PLIC cleanups - Add support for a new variant of the Meson GPIO block - Add support for the irqchip side of the Apple M1 PMU - Add support for the Apple M1 Pro/Max AICv2 irqchip - Add support for the Qualcomm MPM wakeup gadget - Move the Xilinx driver over to the generic irqdomain handling - Tiny speedup for IPIs on GICv3 systems - The usual odd cleanups Link: https://lore.kernel.org/all/20220313105142.704579-1-maz@kernel.org

Merge tag 'irq-api-2022-02-21' into irq/core

2022-02-21T10:33:57Z

Merge the generic_handle_irq_safe() API back into irq/core.

genirq: Provide generic_handle_irq_safe()

2022-02-21T10:31:06Z

Provide generic_handle_irq_safe() which can used from any context. Suggested-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Reviewed-by: Hans de Goede Reviewed-by: Oleksandr Natalenko Reviewed-by: Wolfram Sang Link: https://lore.kernel.org/r/20220211181500.1856198-2-bigeasy@linutronix.de

sched/isolation: Use single feature type while referring to housekeeping cpumask

2022-02-16T14:57:55Z

Refer to housekeeping APIs using single feature types instead of flags. This prevents from passing multiple isolation features at once to housekeeping interfaces, which soon won't be possible anymore as each isolation features will have their own cpumask. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Juri Lelli Reviewed-by: Phil Auld Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org

genirq/debugfs: Use irq_print_chip() when provided by irqchip

2022-02-15T11:22:34Z

Since irqchips have the option to implement irq_print_chip, use this when available to output the irqchip name in debugfs. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220215112154.1360040-1-maz@kernel.org

genirq: Allow irq_chip registration functions to take a const irq_chip

2022-02-15T11:10:21Z

In order to let a const irqchip be fed to the irqchip layer, adjust the various prototypes. An extra cast in irq_set_chip()() is required to avoid a warning. Signed-off-by: Marc Zyngier Acked-by: Linus Walleij Link: https://lore.kernel.org/r/20220209162607.1118325-3-maz@kernel.org