Re: [PATCH 2/3] irqchip/gic-v5: Allow for nr_irqs > 1 for LPI alloc and teardown

From: Sascha Bischoff

Date: Wed May 06 2026 - 05:41:48 EST


On Tue, 2026-05-05 at 22:08 +0200, Thomas Gleixner wrote:
> On Thu, Apr 30 2026 at 15:34, Sascha Bischoff wrote:
> > Formerly the LPI allocaion and freeing was handled by the domains
> > built on top of the LPI domain, and hence the LPI to use was passed
> > in
> > from the child domain. This mandadated that LPI allocation and
> > freeing
> > was done one at a time, rather than for a range of interrupts in
> > one
> > go.
> >
> > Now that the underlying restriction has been removed and all LPI
> > tracking happens within the LPI domain itself, drop the requirement
> > to
> > allocate and free LPIs one-by-one.  While we're at it, clean up the
> > IPI allocation to request all LPIs in one go, rather than
> > requesting
> > them one at a time.
> >
> > Incidentally, this fixes a unwind bug for IPIs where previously
> > allocated entries were not unwound on a failed parent allocation.
>
> See previous reply

Have re-worded this.

>
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@xxxxxxx>
> > ---
> >  drivers/irqchip/irq-gic-v5.c | 70 +++++++++++++++++++-------------
> > ----
> >  1 file changed, 38 insertions(+), 32 deletions(-)
> >
> > diff --git a/drivers/irqchip/irq-gic-v5.c b/drivers/irqchip/irq-
> > gic-v5.c
> > index a3c9eaa8ff486..61a70fe48bc32 100644
> > --- a/drivers/irqchip/irq-gic-v5.c
> > +++ b/drivers/irqchip/irq-gic-v5.c
> > @@ -800,17 +800,16 @@ static void gicv5_irq_lpi_domain_free(struct
> > irq_domain *domain, unsigned int vi
> >         unsigned int nr_irqs)
> >  {
> >   struct irq_data *d;
> > + int i;
> >  
> > - if (WARN_ON_ONCE(nr_irqs != 1))
> > - return;
> > -
> > - d = irq_domain_get_irq_data(domain, virq);
> > -
> > + for (i = 0; i < nr_irqs; i++) {
>
>         for (unsigned int = 0; ....
>
> > + d = irq_domain_get_irq_data(domain, virq + i);
>
>   s/virq/ and then make
>  
>         for (unsigned int = 0; ....; i++, virq++)

Done.

>
> >  static int gicv5_irq_lpi_domain_alloc(struct irq_domain *domain,
> > unsigned int virq,
> > @@ -818,32 +817,38 @@ static int gicv5_irq_lpi_domain_alloc(struct
> > irq_domain *domain, unsigned int vi
> >  {
> >   irq_hw_number_t hwirq;
> >   struct irq_data *irqd;
> > - int ret;
> > -
> > - if (WARN_ON_ONCE(nr_irqs != 1))
> > - return -EINVAL;
> > + int ret, i;
>
> unsigned int i;

Done.

>
> >  static const struct irq_domain_ops gicv5_irq_lpi_domain_ops = {
> > @@ -871,11 +876,11 @@ static int gicv5_irq_ipi_domain_alloc(struct
> > irq_domain *domain, unsigned int vi
> >   struct irq_data *irqd;
> >   int ret, i;
> >  
> > - for (i = 0; i < nr_irqs; i++) {
> > - ret = irq_domain_alloc_irqs_parent(domain, virq +
> > i, 1, NULL);
> > - if (ret)
> > - return ret;
> > + ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
> > arg);
> > + if (ret)
> > + return ret;
> >  
> > + for (i = 0; i < nr_irqs; i++) {
>
>   for (unsigned int i ....

And done.

> Thanks,
>
>         tglx

Version 2 incoming.

Thanks,
Sascha