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

[Lorenzo Pieralisi <lpieralisi@kernel.org>]

On Mon, Jun 08, 2026 at 07:18:15PM +0200, Rafael J. Wysocki wrote:
> On Wed, Jun 3, 2026 at 10:21 AM Lorenzo Pieralisi <lpieralisi@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@kernel.org>
> > Cc: Thomas Gleixner <tglx@kernel.org>
> > Cc: Marc Zyngier <maz@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.

Ok, I will.

> > +
> >         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?

This is a mistake, thanks for spotting it, it belongs in the previous patch
(IMO patch 5 and 6 are a single logical entity, I split it to try to keep
irqchip specific changes in one patch).

iort_iwb_handle() was refactored to return an acpi_handle not a fwnode_handle
(in preparation for adding gic_v5_get_gsi_handle() below - the dependency
chain requires acpi_handle retrieval not fwnode_handle), so the change above
belongs in patch 5, I will move this line change to patch 5 in v3.

Thanks,
Lorenzo

> >
> >         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;
> >
> >
> > --