Re: [PATCH v2 5/7] xen/arm: acpi: add BAD_MADT_GICC_ENTRY() macro

[Julien Grall <julien@xxxxxxx>]

Hi Stefano,

On 24/10/2020 01:32, Stefano Stabellini wrote:
> On Fri, 23 Oct 2020, Julien Grall wrote:
> > From: Julien Grall <julien.grall@xxxxxxx>
> >
> > Imported from Linux commit b6cfb277378ef831c0fa84bcff5049307294adc6:
> >
> >      The BAD_MADT_ENTRY() macro is designed to work for all of the subtables
> >      of the MADT.  In the ACPI 5.1 version of the spec, the struct for the
> >      GICC subtable (struct acpi_madt_generic_interrupt) is 76 bytes long; in
> >      ACPI 6.0, the struct is 80 bytes long.  But, there is only one definition
> >      in ACPICA for this struct -- and that is the 6.0 version.  Hence, when
> >      BAD_MADT_ENTRY() compares the struct size to the length in the GICC
> >      subtable, it fails if 5.1 structs are in use, and there are systems in
> >      the wild that have them.
> >
> >      This patch adds the BAD_MADT_GICC_ENTRY() that checks the GICC subtable
> >      only, accounting for the difference in specification versions that are
> >      possible.  The BAD_MADT_ENTRY() will continue to work as is for all other
> >      MADT subtables.
> >
> >      This code is being added to an arm64 header file since that is currently
> >      the only architecture using the GICC subtable of the MADT.  As a GIC is
> >      specific to ARM, it is also unlikely the subtable will be used elsewhere.
> >
> >      Fixes: aeb823bbacc2 ("ACPICA: ACPI 6.0: Add changes for FADT table.")
> >      Signed-off-by: Al Stone <al.stone@xxxxxxxxxx>
> >      Acked-by: Will Deacon <will.deacon@xxxxxxx>
> >      Acked-by: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> >      [catalin.marinas@xxxxxxx: extra brackets around macro arguments]
> >      Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> >
> > Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
> > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> > Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
> Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Thanks!

> > ---
> >
> > Changes in v2:
> >      - Patch added
> >
> > We may want to consider to also import:
> >
> > commit 9eb1c92b47c73249465d388eaa394fe436a3b489
> > Author: Jeremy Linton <jeremy.linton@xxxxxxx>
> > Date:   Tue Nov 27 17:59:12 2018 +0000
> Sure
I will add it in my todo list of further improvement.

Cheers,

--
Julien Grall