Re: [PATCH v3 3/7] ACPICA: IORT: Add Cavium ThunderX2 SMMUv3 model definition.

From: Will Deacon
Date: Fri May 05 2017 - 10:58:01 EST


On Fri, May 05, 2017 at 07:56:17AM -0700, David Daney wrote:
> On 05/05/2017 06:53 AM, Hanjun Guo wrote:
> >On 2017/5/5 20:08, Geetha sowjanya wrote:
> >>From: Linu Cherian <linu.cherian@xxxxxxxxxx>
> >>
> >>Add SMMUv3 model definition for ThunderX2.
> >>
> >>Signed-off-by: Linu Cherian <linu.cherian@xxxxxxxxxx>
> >>Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@xxxxxxxxxx>
> >>---
> >> include/acpi/actbl2.h | 2 ++
> >> 1 file changed, 2 insertions(+)
> >>
> >>diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
> >>index faa9f2c..76a6f5d 100644
> >>--- a/include/acpi/actbl2.h
> >>+++ b/include/acpi/actbl2.h
> >>@@ -779,6 +779,8 @@ struct acpi_iort_smmu {
> >> #define ACPI_IORT_SMMU_CORELINK_MMU400 0x00000002 /* ARM Corelink
> >>MMU-400 */
> >> #define ACPI_IORT_SMMU_CORELINK_MMU500 0x00000003 /* ARM Corelink
> >>MMU-500 */
> >>
> >>+#define ACPI_IORT_SMMU_V3_CAVIUM_CN99XX 0x00000002 /* Cavium ThunderX2
> >>SMMUv3 */
> >
> >There are some other model numbers in the unreleased spec,
> >I think we need to wait for the updated IORT spec to
> >be released.
> >
>
> ... or if we are fairly confident that the identifier will not need to
> change, we can merge this as is and establish a de facto specification that
> the Real IORT specification will then be forced to follow.
>
> Is there anything other than bureaucratic inertia holding up the real
> specification?

My understanding is that IORT is going to be published imminently (i.e.
before the next kernel release), so it makes sense to wait rather than fork
the spec.

Will