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

From: Thomas Gleixner <[email-masked]>
Date: Tue, 05 May 2026 22:08:55 +0200

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

> Signed-off-by: Sascha Bischoff <[email-masked]>
> ---
>  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++)

>  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;

>  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 ....

Thanks,

        tglx