[PATCH v2 6/6] irqchip/gic-v5: Enable GICv5 IWB ACPI probe ordering detection

[Rafael J. Wysocki]

On Wed, Jun 3, 2026 at 10:21 AM Lorenzo Pieralisi <lpieralisi at kernel.org> wrote:
>
> Register an ACPI hook in the ACPI interrupt management code for GICv5 to
> retrieve the ACPI interrupt controller handle (if any) of the controller
> handling a specific GSI, by updating the acpi_set_irq_model() call with
> the gic_v5_get_gsi_handle() function pointer parameter.
>
> gicv5_get_gsi_handle() allows ACPI core to detect the ACPI handle
> of the controller that manages a specific GSI interrupt.
>
> Update the IWB driver to clear device dependencies in ACPI core once the
> IWB driver has probed.
>
> Signed-off-by: Lorenzo Pieralisi <lpieralisi at kernel.org>
> Cc: Thomas Gleixner <tglx at kernel.org>
> Cc: Marc Zyngier <maz at kernel.org>
> ---
>  drivers/irqchip/irq-gic-v5-iwb.c |  5 +++++
>  drivers/irqchip/irq-gic-v5.c     | 13 +++++++++++--
>  2 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v5-iwb.c b/drivers/irqchip/irq-gic-v5-iwb.c
> index 9103feb70ce8..a02cb9537b15 100644
> --- a/drivers/irqchip/irq-gic-v5-iwb.c
> +++ b/drivers/irqchip/irq-gic-v5-iwb.c
> @@ -269,6 +269,11 @@ static int gicv5_iwb_device_probe(struct platform_device *pdev)
>         if (IS_ERR(iwb_node))
>                 return PTR_ERR(iwb_node);
>
> +#ifdef CONFIG_ACPI
> +       if (has_acpi_companion(&pdev->dev))
> +               acpi_dev_clear_dependencies(ACPI_COMPANION(&pdev->dev));
> +#endif

I would rather add a wrapper for this, along with an empty stub for
the !CONFIG_ACPI case.

> +
>         return 0;
>  }
>
> diff --git a/drivers/irqchip/irq-gic-v5.c b/drivers/irqchip/irq-gic-v5.c
> index 03cc2830b260..26cfaea1af41 100644
> --- a/drivers/irqchip/irq-gic-v5.c
> +++ b/drivers/irqchip/irq-gic-v5.c
> @@ -1217,11 +1217,19 @@ static struct fwnode_handle *gsi_domain_handle;
>  static struct fwnode_handle *gic_v5_get_gsi_domain_id(u32 gsi)
>  {
>         if (FIELD_GET(GICV5_GSI_IC_TYPE, gsi) == GICV5_GSI_IWB_TYPE)
> -               return iort_iwb_handle(FIELD_GET(GICV5_GSI_IWB_FRAME_ID, gsi));
> +               return iort_iwb_handle_fwnode(FIELD_GET(GICV5_GSI_IWB_FRAME_ID, gsi));

Why is this change needed?

>
>         return gsi_domain_handle;
>  }
>
> +static acpi_handle gic_v5_get_gsi_handle(u32 gsi)
> +{
> +       if (FIELD_GET(GICV5_GSI_IC_TYPE, gsi) == GICV5_GSI_IWB_TYPE)
> +               return iort_iwb_handle(FIELD_GET(GICV5_GSI_IWB_FRAME_ID, gsi));
> +
> +       return NULL;
> +}
> +
>  static int __init gic_acpi_init(union acpi_subtable_headers *header, const unsigned long end)
>  {
>         struct acpi_madt_gicv5_irs *irs = (struct acpi_madt_gicv5_irs *)header;
> @@ -1242,7 +1250,8 @@ static int __init gic_acpi_init(union acpi_subtable_headers *header, const unsig
>         if (ret)
>                 goto out_irs;
>
> -       acpi_set_irq_model(ACPI_IRQ_MODEL_GIC_V5, gic_v5_get_gsi_domain_id, NULL);
> +       acpi_set_irq_model(ACPI_IRQ_MODEL_GIC_V5, gic_v5_get_gsi_domain_id,
> +                          gic_v5_get_gsi_handle);
>
>         return 0;
>
>
> --