Re: [PATCH v2 3/7] irqdomain: Add parent field to struct irqchip_fwid

Lorenzo Pieralisi
2026-01-07T08:58:13Z

On Mon, Jan 05, 2026 at 12:01:08PM +0000, Jonathan Cameron wrote:
> On Thu, 18 Dec 2025 11:14:29 +0100
> Lorenzo Pieralisi <lpieralisi@kernel.org> wrote:
>
> > The GICv5 driver IRQ domain hierarchy requires adding a parent field to
> > struct irqchip_fwid so that core code can reference a fwnode_handle parent
> > for a given fwnode.
> >
> > Add a parent field to struct irqchip_fwid and update the related kernel API
> > functions to initialize and handle it.
> >
> > Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Marc Zyngier <maz@kernel.org>
> Hi Lorenzo,
>
> Happy new year.

Happy New Year !

> > ---
> > include/linux/irqdomain.h | 30 ++++++++++++++++++++++++++----
> > kernel/irq/irqdomain.c | 14 +++++++++++++-
> > 2 files changed, 39 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> > index 62f81bbeb490..b9df84b447a1 100644
> > --- a/include/linux/irqdomain.h
> > +++ b/include/linux/irqdomain.h
> > @@ -257,7 +257,8 @@ static inline void irq_domain_set_pm_device(struct irq_domain *d, struct device
> >
> > #ifdef CONFIG_IRQ_DOMAIN
> > struct fwnode_handle *__irq_domain_alloc_fwnode(unsigned int type, int id,
> > - const char *name, phys_addr_t *pa);
> > + const char *name, phys_addr_t *pa,
> > + struct fwnode_handle *parent);
> >
> > enum {
> > IRQCHIP_FWNODE_REAL,
> > @@ -267,18 +268,39 @@ enum {
> >
> > static inline struct fwnode_handle *irq_domain_alloc_named_fwnode(const char *name)
> > {
> > - return __irq_domain_alloc_fwnode(IRQCHIP_FWNODE_NAMED, 0, name, NULL);
> > + return __irq_domain_alloc_fwnode(IRQCHIP_FWNODE_NAMED, 0, name, NULL, NULL);
> > +}
> > +
> > +static inline
> > +struct fwnode_handle *irq_domain_alloc_named_fwnode_parent(const char *name,
> > + struct fwnode_handle *parent)
>
> The name of this makes me think it's allocating the named fwnode parent, rather that
> the named fwnode + setting it's parent.
>
> There aren't all that many calls to irq_domain_named_fwnode(), maybe to avoid challenge
> of a new name, just add the parameter to all of them? (25ish) Mind you the current
> pattern for similar cases is a helper, so maybe not.

Similar cases ? Have you got anything specific I can look into ?

> Or go with something similar to named and have
>
> irq_domain_alloc_named_parented_fwnode()?

Or I can add a set_parent() helper (though that's a bit of churn IMO) ?

If Thomas has a preference I will follow that, all of the above is doable
for me.

> I'm not that bothered though if you think the current naming is the best we can do.

I think you have a point - as per my comment above.

Thanks,
Lorenzo

> Jonathan
>
> > +{
> > + return __irq_domain_alloc_fwnode(IRQCHIP_FWNODE_NAMED, 0, name, NULL, parent);
> > }
>
>