Re: [PATCH v3 02/26] ACPI: irq: Add IRQ affinity reporting interface

Rafael J. Wysocki
2025-09-22T17:10:13Z

On Mon, Sep 22, 2025 at 10:28 AM Marc Zyngier <maz@kernel.org> wrote:
>
> Plug the irq_populate_fwspec_info() helper into the ACPI layer
> to offer an IRQ affinity reporting function. This is currently
> only supported for the CONFIG_ACPI_GENERIC_GSI configurations,
> but could later be extended to legacy architectures if necessary.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>

> ---
> drivers/acpi/irq.c | 19 +++++++++++++++++++
> include/linux/acpi.h | 7 +++++++
> 2 files changed, 26 insertions(+)
>
> diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
> index 76a856c32c4d0..d1595156c86a4 100644
> --- a/drivers/acpi/irq.c
> +++ b/drivers/acpi/irq.c
> @@ -300,6 +300,25 @@ int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
> }
> EXPORT_SYMBOL_GPL(acpi_irq_get);
>
> +const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
> + unsigned int index)
> +{
> + struct irq_fwspec_info info;
> + struct irq_fwspec fwspec;
> + unsigned long flags;
> +
> + if (acpi_irq_parse_one(handle, index, &fwspec, &flags))
> + return NULL;
> +
> + if (irq_populate_fwspec_info(&fwspec, &info))
> + return NULL;
> +
> + if (!(info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID))
> + return NULL;
> +
> + return info.affinity;
> +}
> +
> /**
> * acpi_set_irq_model - Setup the GSI irqdomain information
> * @model: the value assigned to acpi_irq_model
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 1c5bb1e887cd1..c506ae4bacc86 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -1509,12 +1509,19 @@ static inline int acpi_parse_spcr(bool enable_earlycon, bool enable_console)
>
> #if IS_ENABLED(CONFIG_ACPI_GENERIC_GSI)
> int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res);
> +const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
> + unsigned int index);
> #else
> static inline
> int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
> {
> return -EINVAL;
> }
> +static inline const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
> + unsigned int index)
> +{
> + return NULL;
> +}
> #endif
>
> #ifdef CONFIG_ACPI_LPIT
> --
> 2.47.3
>