Re: [PATCH Dovetail v2 1/2] dovetail: genirq: Add request_percpu_irq_affinity_flags()

[Philippe Gerum <rpm@xenomai.org>]

Florian Bezdeka <florian.bezdeka@siemens.com> writes:

> On Thu, 2026-02-19 at 18:10 +0100, Philippe Gerum wrote:
>> Florian Bezdeka <florian.bezdeka@siemens.com> writes:
>> 
>> > On Wed, 2026-02-18 at 08:30 +0100, Jan Kiszka wrote:
>> > > On 18.02.26 00:05, Florian Bezdeka wrote:
>> > > > On Tue, 2026-02-17 at 23:54 +0100, Florian Bezdeka wrote:
>> > > > > cobalt / evl are currently using __request_percpu_irq() for setting up
>> > > > > OOB IRQs. In 6.19 the signature of __request_percpu_irq() has been
>> > > > > updated and 7.0 will remove the function entirely, so we need a
>> > > > > replacement.
>> > > > > 
>> > > > > All other variants (like the upcoming request_percpu_irq_affinity())
>> > > > > are missing the flags parameter which we require.
>> > > > > 
>> > > > > This could be backported to all supported dovetail versions. That
>> > > > > would allow co-kernels to switch to the new API unconditionally.
>> > > > > 
>> > > > > Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
>> > > > > ---
>> > > > >  include/linux/interrupt.h |  5 +++++
>> > > > >  kernel/irq/manage.c       | 10 ++++++++++
>> > > > >  2 files changed, 15 insertions(+)
>> > > > > 
>> > > > > diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
>> > > > > index bf0511b438c65e119af917763ce92a8f3bfb4c4c..6cd8ad02ffbd87f71869d6737fbc8c1ae477c1ee 100644
>> > > > > --- a/include/linux/interrupt.h
>> > > > > +++ b/include/linux/interrupt.h
>> > > > > @@ -213,6 +213,11 @@ request_percpu_irq_affinity(unsigned int irq, irq_handler_t handler,
>> > > > >  				    devname, affinity, percpu_dev_id);
>> > > > >  }
>> > > > >  
>> > > > > +int request_percpu_irq_affinity_flags(unsigned int irq, irq_handler_t handler,
>> > > > > +				      unsigned long flags, const char *devname,
>> > > > > +				      const cpumask_t *affinity,
>> > > > > +				      void __percpu *dev_id);
>> > > > > +
>> > > > > 
>> > > > 
>> > > > Would be nice to get some feedback here. The affinity parameter is
>> > > > currently not in use, but would allow us to provide it in the future.
>> > > > Not sure if that will be necessary...
>> > > > 
>> > > 
>> > > This is what I was wondering as well... When would one need that? Maybe
>> > > in the context of confining Xenomai to a subset of physical CPUs? Would
>> > > be good to check that again.
>> > 
>> > @Philippe: Any thoughts?
>> > 
>> > I would like to complete the 6.19 port on Xenomai side. This is a
>> > blocker right now.
>> > 
>> 
>> To me this is a no-brainer, given that __request_percpu_irq() requires
>> an affinity mask, having request_percpu_irq_affinity_flags() is the only
>> sane way to set all the properties of a per-cpu interrupt, including
>> flags and affinity, in one go. In any case, callers who don't care about
>> such affinity can pass NULL.
>> 
>
> Thanks for the confirmation. 
>
> I will add the series now to the wip/flo/v6.19-dovetail-rebase branch
> and continue with the Xeno 3 adaptions. evl will need the same changes.
> Philippe, can you look into that or should I try to reserve some cycles?
>
> The Xeno 3 testsuite is already passing on that branch.

Ok. I'll handle the x4 updates.

-- 
Philippe.