linux-toradex.git/include/linux/irq_work.h, branch v6.16-rc5

arch: consolidate arch_irq_work_raise prototypes

2023-11-23T10:32:29+00:00

The prototype was hidden in an #ifdef on x86, which causes a warning:

kernel/irq_work.c:72:13: error: no previous prototype for 'arch_irq_work_raise' [-Werror=missing-prototypes]

Some architectures have a working prototype, while others don't.
Fix this by providing it in only one place that is always visible.

Reviewed-by: Alexander Gordeev 
Acked-by: Catalin Marinas 
Acked-by: Palmer Dabbelt 
Acked-by: Guo Ren 
Signed-off-by: Arnd Bergmann

irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT

2021-10-15T09:25:18+00:00

On PREEMPT_RT most items are processed as LAZY via softirq context.
Avoid to spin-wait for them because irq_work_sync() could have higher
priority and not allow the irq-work to be completed.

Wait additionally for !IRQ_WORK_HARD_IRQ irq_work items on PREEMPT_RT.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20211006111852.1514359-5-bigeasy@linutronix.de

irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.

2021-10-15T09:25:17+00:00

irq_work() triggers instantly an interrupt if supported by the
architecture. Otherwise the work will be processed on the next timer
tick. In worst case irq_work_sync() could spin up to a jiffy.

irq_work_sync() is usually used in tear down context which is fully
preemptible. Based on review irq_work_sync() is invoked from preemptible
context and there is one waiter at a time. This qualifies it to use
rcuwait for synchronisation.

Let irq_work_sync() synchronize with rcuwait if the architecture
processes irqwork via the timer tick.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20211006111852.1514359-3-bigeasy@linutronix.de

irq_work: Cleanup

2020-11-24T15:47:48+00:00

Get rid of the __call_single_node union and clean up the API a little
to avoid external code relying on the structure layout as much.

Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Frederic Weisbecker

smp, irq_work: Continue smp_call_function() and irq_work() integration

2020-06-28T15:01:20+00:00

Instead of relying on BUG_ON() to ensure the various data structures
line up, use a bunch of horrible unions to make it all automatic.

Much of the union magic is to ensure irq_work and smp_call_function do
not (yet) see the members of their respective data structures change
name.

Suggested-by: Linus Torvalds 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Reviewed-by: Frederic Weisbecker 
Link: https://lkml.kernel.org/r/20200622100825.844455025@infradead.org

irq_work: Define irq_work_single() on !CONFIG_IRQ_WORK too

2020-06-02T10:34:45+00:00

Some SMP platforms don't have CONFIG_IRQ_WORK defined, resulting in a link
error at build time.

Define a stub and clean up the prototype definitions.

Reported-by: kbuild test robot 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

irq_work, smp: Allow irq_work on call_single_queue

2020-05-28T08:54:15+00:00

Currently irq_work_queue_on() will issue an unconditional
arch_send_call_function_single_ipi() and has the handler do
irq_work_run().

This is unfortunate in that it makes the IPI handler look at a second
cacheline and it misses the opportunity to avoid the IPI. Instead note
that struct irq_work and struct __call_single_data are very similar in
layout, so use a few bits in the flags word to encode a type and stick
the irq_work on the call_single_queue list.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/20200526161908.011635912@infradead.org

lockdep: Annotate irq_work

2020-03-21T15:00:24+00:00

Mark irq_work items with IRQ_WORK_HARD_IRQ which should be invoked in
hardirq context even on PREEMPT_RT. IRQ_WORK without this flag will be
invoked in softirq context on PREEMPT_RT.

Set ->irq_config to 1 for the IRQ_WORK items which are invoked in softirq
context so lockdep knows that these can safely acquire a spinlock_t.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20200321113242.643576700@linutronix.de

irq_work: Convert flags to atomic_t

2019-11-11T08:02:56+00:00

We need to convert flags to atomic_t in order to later fix an ordering
issue on atomic_cmpxchg() failure. This will allow us to use atomic_fetch_or().

Also clarify the nature of those flags.

[ mingo: Converted two more usage site the original patch missed. ]

Signed-off-by: Frederic Weisbecker 
Cc: Linus Torvalds 
Cc: Paul E . McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20191108160858.31665-2-frederic@kernel.org
Signed-off-by: Ingo Molnar

irq/work: Improve the flag definitions

2018-01-08T18:43:15+00:00

IRQ_WORK_FLAGS is defined simply to 3UL. This is confusing as it
says nothing about its purpose. Define IRQ_WORK_FLAGS as a bitwise
OR of IRQ_WORK_PENDING and IRQ_WORK_BUSY and change its name to
IRQ_WORK_CLAIMED.

While we're at it: use the BIT() macro for all flags.

Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Frederic Weisbecker 
Reviewed-by: Andy Shevchenko 
Cc: Linus Torvalds 
Cc: Marc Zyngier 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1515125996-21564-1-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar