Re: [PATCH 1/3] cobalt: Prepare for new signature of __request_percpu_irq() in 6.19

On Mon, 2026-02-16 at 12:43 +0100, Jan Kiszka wrote:
> On 16.02.26 12:22, Florian Bezdeka wrote:
> > On Mon, 2026-02-16 at 12:16 +0100, Jan Kiszka wrote:
> > > On 16.02.26 12:15, Florian Bezdeka wrote:
> > > > On Mon, 2026-02-16 at 12:11 +0100, Jan Kiszka wrote:
> > > > > On 16.02.26 11:58, Florian Bezdeka wrote:
> > > > > > Since 6.19 the signature of __request_percpu_irq() got one additional
> > > > > > affinity parameter.
> > > > > > 
> > > > > > A new Linux version specific wrapper cobalt_request_percpu_irq() is
> > > > > > introduced to hide the signature change between different Linux
> > > > > > versions.
> > > > > > 
> > > > > > Signed-off-by: Florian Bezdeka <[email protected]>
> > > > > > ---
> > > > > >  include/cobalt/kernel/dovetail/pipeline/irq.h      | 20 ++++++++++++++++++++
> > > > > >  include/cobalt/kernel/dovetail/pipeline/pipeline.h | 10 +++++-----
> > > > > >  include/cobalt/kernel/dovetail/pipeline/sirq.h     |  8 +++-----
> > > > > >  kernel/cobalt/dovetail/tick.c                      |  8 ++++----
> > > > > >  4 files changed, 32 insertions(+), 14 deletions(-)
> > > > > > 
> > > > > > diff --git a/include/cobalt/kernel/dovetail/pipeline/irq.h b/include/cobalt/kernel/dovetail/pipeline/irq.h
> > > > > > index 55d9b8ff17cd08e5e8c09aec393a1e23736c1b76..ac780a4bb3223889ccf827b5b8cb279035a5dd7b 100644
> > > > > > --- a/include/cobalt/kernel/dovetail/pipeline/irq.h
> > > > > > +++ b/include/cobalt/kernel/dovetail/pipeline/irq.h
> > > > > > @@ -5,6 +5,26 @@
> > > > > >  #ifndef _COBALT_KERNEL_DOVETAIL_IRQ_H
> > > > > >  #define _COBALT_KERNEL_DOVETAIL_IRQ_H
> > > > > >  
> > > > > > +#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 19, 0)
> > > > > > +static inline int cobalt_request_percpu_irq(unsigned int irq,
> > > > > > +					    irq_handler_t handler,
> > > > > > +					    unsigned long flags,
> > > > > > +					    const char *devname,
> > > > > > +					    void __percpu *dev_id)
> > > > > > +{
> > > > > > +	return __request_percpu_irq(irq, handler, flags, devname, dev_id);
> > > > > > +}
> > > > > > +#else
> > > > > > +static inline int cobalt_request_percpu_irq(unsigned int irq,
> > > > > > +					    irq_handler_t handler,
> > > > > > +					    unsigned long flags,
> > > > > > +					    const char *devname,
> > > > > > +					    void __percpu *dev_id)
> > > > > > +{
> > > > > > +	return __request_percpu_irq(irq, handler, flags, devname, NULL, dev_id);
> > > > > > +}
> > > > > > +#endif
> > > > > 
> > > > > Please use a define for request_percpu_irq on older kernels that uses
> > > > > the new signature and resolves to the old one via __request_percpu_irq
> > > > > as needed. 
> > > > > Yes, also switch to request_percpu_irq directly because
> > > > > __request_percpu_irq is going to be removed in 7.0.
> > > > > 
> > > > 
> > > > request_percpu_irq() doesn't allow us to specify the flags. IRQF_OOB and
> > > > IRQF_NO_THREAD would be needed.
> > > 
> > > Then request_percpu_irq_affinity - whatever survives 7.0 already as well.
> > > 
> > 
> > No flags as well. 
> > 
> > I was not aware of __request_percpu_irq() being renamed in 7.0. Will try
> > to find something else, but that doesn't look promising at the moment.
> > 
> 
> Ouch, indeed, trouble ahead (or extra API needed from dovetail). If this
> becomes a blocker moving forward with 6.19, just re-#define
> __request_percpu_irq for now.

This is what this patch does, avoiding a strange function name override.

Anyhow, as this way turned out to be not future prove I might have to
provide an additional API in dovetail. Evl should have the same problem,
so reuse seems likely.