Re: [PATCH edk2-platforms 1/1] Silicon/Qemu: don't advertise GICC legacy mmio interface in SbsaQamu MADT

["Leif Lindholm" <leif@nuviainc.com>]

On Fri, Oct 08, 2021 at 16:18:44 +0200, Ard Biesheuvel wrote:
> On Fri, 8 Oct 2021 at 12:34, Leif Lindholm <leif@nuviainc.com> wrote:
> >
> > The MADT GICC structure contains the field PhysicalBaseAddress, which
> > is needed for a GICv1/v2 implementation, or to indicate legacy
> > compatibility in modern GICs.
> >
> > Linux commit 9739f6ef053f1, included in v5.12, adds a warning message
> > when this field is populated but invalid:
> >   [Firmware Bug]: CPU interface incapable of MMIO access
> >
> > As it happens, we currently initialize this to PcdGicDistributorBase
> > instead of PcdGicInterruptInterfaceBase, and as a result we now trigger
> > this warning.
> >
> > Since this is an SBSA reference implementation, and legacy GIC support
> > has never worked for this port, set the field to 0.
> >
> > Signed-off-by: Leif Lindholm <leif@nuviainc.com>
> > Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> > Cc: Graeme Gregory <graeme@nuviainc.com>
> > Cc: Radoslaw Biernacki <rad@semihalf.com>
> 
> Acked-by: Ard Biesheuvel <ardb@kernel.org>

Thanks - pushed as 69035742d336.

/
    Leif

> > ---
> >  Silicon/Qemu/SbsaQemu/Drivers/SbsaQemuAcpiDxe/SbsaQemuAcpiDxe.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/Silicon/Qemu/SbsaQemu/Drivers/SbsaQemuAcpiDxe/SbsaQemuAcpiDxe.c b/Silicon/Qemu/SbsaQemu/Drivers/SbsaQemuAcpiDxe/SbsaQemuAcpiDxe.c
> > index b8901030ecd0..dbc5e9475358 100644
> > --- a/Silicon/Qemu/SbsaQemu/Drivers/SbsaQemuAcpiDxe/SbsaQemuAcpiDxe.c
> > +++ b/Silicon/Qemu/SbsaQemu/Drivers/SbsaQemuAcpiDxe/SbsaQemuAcpiDxe.c
> > @@ -71,7 +71,7 @@ AddMadtTable (
> >      0,                                     /* Mpidr */
> >      EFI_ACPI_6_0_GIC_ENABLED,              /* Flags */
> >      SBSAQEMU_MADT_GIC_PMU_IRQ,             /* PMU Irq */
> > -    FixedPcdGet32 (PcdGicDistributorBase), /* PhysicalBaseAddress */
> > +    0,                                     /* PhysicalBaseAddress */
> >      SBSAQEMU_MADT_GIC_VBASE,               /* GicVBase */
> >      SBSAQEMU_MADT_GIC_HBASE,               /* GicHBase */
> >      25,                                    /* GsivId */
> > --
> > 2.30.2
> >