Pull irq core updates from Thomas Gleixner:
"Updates for the interrupt core subsystem:
- Remove the interrupt timing infrastructure
This was added seven years ago to be used for power management
purposes, but that integration never happened.
- Clean up the remaining setup_percpu_irq() users
The memory allocator is available when interrupts can be requested
so there is not need for static irq_action. Move the remaining
users to request_percpu_irq() and delete the historical cruft.
- Warn when interrupt flag inconsistencies are detected in
request*_irq().
Inconsistent flags can lead to hard to diagnose malfunction. The
fallout of this new warning has been addressed in next and the
fixes are coming in via the maintainer trees and the tip
irq/cleanup pull requests.
- Invoke affinity notifier when CPU hotplug breaks affinity
Otherwise the code using the notifier misses the affinity change
and operates on stale information.
- The usual cleanups and improvements"
* tag 'irq-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/proc: Replace snprintf with strscpy in register_handler_proc
genirq/cpuhotplug: Notify about affinity changes breaking the affinity mask
genirq: Move clear of kstat_irqs to free_desc()
genirq: Warn about using IRQF_ONESHOT without a threaded handler
irqdomain: Fix up const problem in irq_domain_set_name()
genirq: Remove setup_percpu_irq()
clocksource/drivers/mips-gic-timer: Move GIC timer to request_percpu_irq()
MIPS: Move IP27 timer to request_percpu_irq()
MIPS: Move IP30 timer to request_percpu_irq()
genirq: Remove __request_percpu_irq() helper
genirq: Remove IRQ timing tracking infrastructure
The flag IRQF_COND_ONESHOT was already force-added to request_irq() because
the ACPI SCI interrupt handler is using the IRQF_ONESHOT flag which breaks
all shared handlers.
devm_request_irq() needs the same change since some users, such as
int0002_vgpio, are using this function instead.
Add IRQF_COND_ONESHOT to the flags passed to devm_request_irq().
Fixes: c37927a203 ("genirq: Set IRQF_COND_ONESHOT in request_irq()")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260128095540.863589-2-bigeasy@linutronix.de
With the IRQ timing stuff being gone, there is no need to specify a flag
when requesting a percpu interrupt. Not only IRQF_TIMER was the only flag
(set of flags actually) allowed, but nobody ever passed it.
Get rid of __request_percpu_irq(), which was only getting 0 as flags, and
promote request_percpu_irq_affinity() as its replacement.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20251210082242.360936-3-maz@kernel.org
While it would be nice to simply make request_percpu_irq() take an affinity
mask, the churn is likely to be on the irritating side given that most
drivers do not give a damn about affinities.
So take the more innocuous path to provide a helper that parallels
request_percpu_irq(), with an affinity as a bonus argument.
Yes, request_percpu_irq_affinity() is a bit of a mouthful.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-18-maz@kernel.org
Add an affinity field to both the irqaction structure and the interrupt
request primitives. Nothing is making use of it yet, and the only value
used it NULL, which is used as a shorthand for cpu_possible_mask.
This will shortly get used with actual affinities.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-15-maz@kernel.org
When irqaction::percpu_dev_id was introduced, it was hoped that it could be
part of an anonymous union with dev_id, as the two fields are mutually
exclusive.
However, toolchains used at the time were often showing terrible support
for anonymous unions, breaking the build on a number of architectures. It
was therefore decided to keep the two fields separate and address this down
the line.
14 years later, the compiler dark age is over, and there is universal
support for anonymous unions. Get a whole pointer back that can immediately
be spent on something else.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-13-maz@kernel.org
disable_irq_nosync_lockdep() disables interrupts with lockdep enabled to
avoid false positive reports by lockdep that a certain lock has not been
acquired with disabled interrupts. The user of this macros expects that
a lock can be acquried without disabling interrupts because the IRQ line
triggering the interrupt is disabled.
This triggers a warning on PREEMPT_RT because after
disable_irq_nosync_lockdep.*() the following spinlock_t now is acquired
with disabled interrupts.
On PREEMPT_RT there is no difference between spin_lock() and
spin_lock_irq() so avoiding disabling interrupts in this case works for
the two remaining callers as of today.
Don't disable interrupts on PREEMPT_RT in disable_irq_nosync_lockdep.*().
Closes: https://lore.kernel.org/760e34f9-6034-40e0-82a5-ee9becd24438@roeck-us.net
Fixes: e8106b941c ("[PATCH] lockdep: core, add enable/disable_irq_irqsave/irqrestore() APIs")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Suggested-by: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20250212103619.2560503-2-bigeasy@linutronix.de
The timer and hrtimer soft interrupts are raised in hard interrupt
context. With threaded interrupts force enabled or on PREEMPT_RT this leads
to waking the ksoftirqd for the processing of the soft interrupt.
ksoftirqd runs as SCHED_OTHER task which means it will compete with other
tasks for CPU resources. This can introduce long delays for timer
processing on heavy loaded systems and is not desired.
Split the TIMER_SOFTIRQ and HRTIMER_SOFTIRQ processing into a dedicated
timers thread and let it run at the lowest SCHED_FIFO priority.
Wake-ups for RT tasks happen from hardirq context so only timer_list timers
and hrtimers for "regular" tasks are processed here. The higher priority
ensures that wakeups are performed before scheduling SCHED_OTHER tasks.
Using a dedicated variable to store the pending softirq bits values ensure
that the timer are not accidentally picked up by ksoftirqd and other
threaded interrupts.
It shouldn't be picked up by ksoftirqd since it runs at lower priority.
However if ksoftirqd is already running while a timer fires, then ksoftird
will be PI-boosted due to the BH-lock to ktimer's priority.
The timer thread can pick up pending softirqs from ksoftirqd but only
if the softirq load is high. It is not be desired that the picked up
softirqs are processed at SCHED_FIFO priority under high softirq load
but this can already happen by a PI-boost by a force-threaded interrupt.
[ frederic@kernel.org: rcutorture.c fixes, storm fix by introduction of
local_timers_pending() for tick_nohz_next_event() ]
[ junxiao.chang@intel.com: Ensure ktimersd gets woken up even if a
softirq is currently served. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org> [rcutorture]
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241106150419.2593080-4-bigeasy@linutronix.de
When soft interrupt actions are called, they are passed a pointer to the
struct softirq action which contains the action's function pointer.
This pointer isn't useful, as the action callback already knows what
function it is. And since each callback handles a specific soft interrupt,
the callback also knows which soft interrupt number is running.
No soft interrupt action callback actually uses this parameter, so remove
it from the function pointer signature. This clarifies that soft interrupt
actions are global routines and makes it slightly cheaper to call them.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/all/20240815171549.3260003-1-csander@purestorage.com
Pull interrupt subsystem updates from Thomas Gleixner:
"Core:
- Provide a new mechanism to create interrupt domains. The existing
interfaces have already too many parameters and it's a pain to
expand any of this for new required functionality.
The new function takes a pointer to a data structure as argument.
The data structure combines all existing parameters and allows for
easy extension.
The first extension for this is to handle the instantiation of
generic interrupt chips at the core level and to allow drivers to
provide extra init/exit callbacks.
This is necessary to do the full interrupt chip initialization
before the new domain is published, so that concurrent usage sites
won't see a half initialized interrupt domain. Similar problems
exist on teardown.
This has turned out to be a real problem due to the deferred and
parallel probing which was added in recent years.
Handling this at the core level allows to remove quite some accrued
boilerplate code in existing drivers and avoids horrible
workarounds at the driver level.
- The usual small improvements all over the place
Drivers:
- Add support for LAN966x OIC and RZ/Five SoC
- Split the STM ExtI driver into a microcontroller and a SMP version
to allow building the latter as a module for multi-platform
kernels
- Enable MSI support for Armada 370XP on platforms which do not
support IPIs
- The usual small fixes and enhancements all over the place"
* tag 'irq-core-2024-07-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits)
irqdomain: Fix the kernel-doc and plug it into Documentation
genirq: Set IRQF_COND_ONESHOT in request_irq()
irqchip/imx-irqsteer: Handle runtime power management correctly
irqchip/gic-v3: Pass #redistributor-regions to gic_of_setup_kvm_info()
irqchip/bcm2835: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND
irqchip/gic-v4: Make sure a VPE is locked when VMAPP is issued
irqchip/gic-v4: Substitute vmovp_lock for a per-VM lock
irqchip/gic-v4: Always configure affinity on VPE activation
Revert "irqchip/dw-apb-ictl: Support building as module"
Revert "Loongarch: Support loongarch avec"
arm64: Kconfig: Allow build irq-stm32mp-exti driver as module
ARM: stm32: Allow build irq-stm32mp-exti driver as module
irqchip/stm32mp-exti: Allow building as module
irqchip/stm32mp-exti: Rename internal symbols
irqchip/stm32-exti: Split MCU and MPU code
arm64: Kconfig: Select STM32MP_EXTI on STM32 platforms
ARM: stm32: Use different EXTI driver on ARMv7m and ARMv7a
irqchip/stm32-exti: Add CONFIG_STM32MP_EXTI
irqchip/dw-apb-ictl: Support building as module
irqchip/riscv-aplic: Simplify the initialization code
...
Pull non-MM updates from Andrew Morton:
- In the series "treewide: Refactor heap related implementation",
Kuan-Wei Chiu has significantly reworked the min_heap library code
and has taught bcachefs to use the new more generic implementation.
- Yury Norov's series "Cleanup cpumask.h inclusion in core headers"
reworks the cpumask and nodemask headers to make things generally
more rational.
- Kuan-Wei Chiu has sent along some maintenance work against our
sorting library code in the series "lib/sort: Optimizations and
cleanups".
- More library maintainance work from Christophe Jaillet in the series
"Remove usage of the deprecated ida_simple_xx() API".
- Ryusuke Konishi continues with the nilfs2 fixes and clanups in the
series "nilfs2: eliminate the call to inode_attach_wb()".
- Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix
GDB command error".
- Plus the usual shower of singleton patches all over the place. Please
see the relevant changelogs for details.
* tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits)
ia64: scrub ia64 from poison.h
watchdog/perf: properly initialize the turbo mode timestamp and rearm counter
tsacct: replace strncpy() with strscpy()
lib/bch.c: use swap() to improve code
test_bpf: convert comma to semicolon
init/modpost: conditionally check section mismatch to __meminit*
init: remove unused __MEMINIT* macros
nilfs2: Constify struct kobj_type
nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro
math: rational: add missing MODULE_DESCRIPTION() macro
lib/zlib: add missing MODULE_DESCRIPTION() macro
fs: ufs: add MODULE_DESCRIPTION()
lib/rbtree.c: fix the example typo
ocfs2: add bounds checking to ocfs2_check_dir_entry()
fs: add kernel-doc comments to ocfs2_prepare_orphan_dir()
coredump: simplify zap_process()
selftests/fpu: add missing MODULE_DESCRIPTION() macro
compiler.h: simplify data_race() macro
build-id: require program headers to be right after ELF header
resource: add missing MODULE_DESCRIPTION()
...
Drivers often need to first disable an interrupt, carry out some
action, and then reenable the interrupt. Introduce support for the
"guard" notation for this so that the following is possible:
...
scoped_cond_guard(mutex_intr, return -EINTR, &data->sysfs_mutex) {
guard(disable_irq)(&client->irq);
error = elan_acquire_baseline(data);
if (error)
return error;
}
...
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/ZljAV6HjkPSEhWSw@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
There is a problem when a driver requests a shared interrupt line to run a
threaded handler on it without IRQF_ONESHOT set if that flag has been set
already for the IRQ in question by somebody else. Namely, the request
fails which usually leads to a probe failure even though the driver might
have worked just fine with IRQF_ONESHOT, but it does not want to use it by
default. Currently, the only way to handle this is to try to request the
IRQ without IRQF_ONESHOT, but with IRQF_PROBE_SHARED set and if this fails,
try again with IRQF_ONESHOT set. However, this is a bit cumbersome and not
very clean.
When commit 7a36b901a6 ("ACPI: OSL: Use a threaded interrupt handler for
SCI") switched the ACPI subsystem over to using a threaded interrupt
handler for the SCI, it had to use IRQF_ONESHOT for it because that's
required due to the way the SCI handler works (it needs to walk all of the
enabled GPEs before the interrupt line can be unmasked). The SCI interrupt
line is not shared with other users very often due to the SCI handling
overhead, but on sone systems it is shared and when the other user of it
attempts to install a threaded handler, a flags mismatch related to
IRQF_ONESHOT may occur.
As it turned out, that happened to the pinctrl-amd driver and so commit
4451e8e841 ("pinctrl: amd: Add IRQF_ONESHOT to the interrupt request")
attempted to address the issue by adding IRQF_ONESHOT to the interrupt
flags in that driver, but this is now causing an IRQF_ONESHOT-related
mismatch to occur on another system which cannot boot as a result of it.
Clearly, pinctrl-amd can work with IRQF_ONESHOT if need be, but it should
not set that flag by default, so it needs a way to indicate that to the
interrupt subsystem.
To that end, introdcuce a new interrupt flag, IRQF_COND_ONESHOT, which will
only have effect when the IRQ line is shared and IRQF_ONESHOT has been set
for it already, in which case it will be promoted to the latter.
This is sufficient for drivers sharing the interrupt line with the SCI as
it is requested by the ACPI subsystem before any drivers are probed, so
they will always see IRQF_ONESHOT set for the interrupt in question.
Fixes: 4451e8e841 ("pinctrl: amd: Add IRQF_ONESHOT to the interrupt request")
Reported-by: Francisco Ayala Le Brun <francisco@videowindow.eu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: 6.8+ <stable@vger.kernel.org> # 6.8+
Closes: https://lore.kernel.org/lkml/CAN-StX1HqWqi+YW=t+V52-38Mfp5fAz7YHx4aH-CQjgyNiKx3g@mail.gmail.com/
Link: https://lore.kernel.org/r/12417336.O9o76ZdvQC@kreacher
Pull RCU updates from Frederic Weisbecker:
- RCU torture, locktorture and generic torture infrastructure updates
that include various fixes, cleanups and consolidations.
Among the user visible things, ftrace dumps can now be found into
their own file, and module parameters get better documented and
reported on dumps.
- Generic and misc fixes all over the place. Some highlights:
* Hotplug handling has seen some light cleanups and comments
* An RCU barrier can now be triggered through sysfs to serialize
memory stress testing and avoid OOM
* Object information is now dumped in case of invalid callback
invocation
* Also various SRCU issues, too hard to trigger to deserve urgent
pull requests, have been fixed
- RCU documentation updates
- RCU reference scalability test minor fixes and doc improvements.
- RCU tasks minor fixes
- Stall detection updates. Introduce RCU CPU Stall notifiers that
allows a subsystem to provide informations to help debugging. Also
cure some false positive stalls.
* tag 'rcu-next-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: (56 commits)
srcu: Only accelerate on enqueue time
locktorture: Check the correct variable for allocation failure
srcu: Fix callbacks acceleration mishandling
rcu: Comment why callbacks migration can't wait for CPUHP_RCUTREE_PREP
rcu: Standardize explicit CPU-hotplug calls
rcu: Conditionally build CPU-hotplug teardown callbacks
rcu: Remove references to rcu_migrate_callbacks() from diagrams
rcu: Assume rcu_report_dead() is always called locally
rcu: Assume IRQS disabled from rcu_report_dead()
rcu: Use rcu_segcblist_segempty() instead of open coding it
rcu: kmemleak: Ignore kmemleak false positives when RCU-freeing objects
srcu: Fix srcu_struct node grpmask overflow on 64-bit systems
torture: Convert parse-console.sh to mktemp
rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle()
rcutorture: Replace schedule_timeout*() 1-jiffy waits with HZ/20
torture: Add kvm.sh --debug-info argument
locktorture: Rename readers_bind/writers_bind to bind_readers/bind_writers
doc: Catch-up update for locktorture module parameters
locktorture: Add call_rcu_chains module parameter
locktorture: Add new module parameters to lock_torture_print_module_parms()
...
rcu_report_dead() and rcutree_migrate_callbacks() have their headers in
rcupdate.h while those are pure rcutree calls, like the other CPU-hotplug
functions.
Also rcu_cpu_starting() and rcu_report_dead() have different naming
conventions while they mirror each other's effects.
Fix the headers and propose a naming that relates both functions and
aligns with the prefix of other rcutree CPU-hotplug functions.
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Specific stress involving frequent CPU-hotplug operations, such as
running rcutorture for example, may trigger the following message:
NOHZ tick-stop error: local softirq work is pending, handler #02!!!"
This happens in the CPU-down hotplug process, after
CPUHP_AP_SMPBOOT_THREADS whose teardown callback parks ksoftirqd, and
before the target CPU shuts down through CPUHP_AP_IDLE_DEAD. In this
fragile intermediate state, softirqs waiting for threaded handling may be
forever ignored and eventually reported by the idle task as in the above
example.
However some vectors are known to be safe as long as the corresponding
subsystems have teardown callbacks handling the migration of their
events. The above error message reports pending timers softirq although
this vector can be considered as hotplug safe because the
CPUHP_TIMERS_PREPARE teardown callback performs the necessary migration
of timers after the death of the CPU. Hrtimers also have a similar
hotplug handling.
Therefore this error message, as far as (hr-)timers are concerned, can
be considered spurious and the relevant softirq vectors can be marked as
hotplug safe.
Fixes: 0345691b24 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230912104406.312185-6-frederic@kernel.org
Pull scheduler updates from Ingo Molnar:
- Updates to scheduler metrics:
- PELT fixes & enhancements
- PSI fixes & enhancements
- Refactor cpu_util_without()
- Updates to instrumentation/debugging:
- Remove sched_trace_*() helper functions - can be done via debug
info
- Fix double update_rq_clock() warnings
- Introduce & use "preemption model accessors" to simplify some of the
Kconfig complexity.
- Make softirq handling RT-safe.
- Misc smaller fixes & cleanups.
* tag 'sched-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
topology: Remove unused cpu_cluster_mask()
sched: Reverse sched_class layout
sched/deadline: Remove superfluous rq clock update in push_dl_task()
sched/core: Avoid obvious double update_rq_clock warning
smp: Make softirq handling RT safe in flush_smp_call_function_queue()
smp: Rename flush_smp_call_function_from_idle()
sched: Fix missing prototype warnings
sched/fair: Remove cfs_rq_tg_path()
sched/fair: Remove sched_trace_*() helper functions
sched/fair: Refactor cpu_util_without()
sched/fair: Revise comment about lb decision matrix
sched/psi: report zeroes for CPU full at the system level
sched/fair: Delete useless condition in tg_unthrottle_up()
sched/fair: Fix cfs_rq_clock_pelt() for throttled cfs_rq
sched/fair: Move calculate of avg_load to a better location
mailmap: Update my email address to @redhat.com
MAINTAINERS: Add myself as scheduler topology reviewer
psi: Fix trigger being fired unexpectedly at initial
ftrace: Use preemption model accessors for trace header printout
kcsan: Use preemption model accessors
