Re: [PATCH v3 0/7] Cavium ThunderX2 SMMUv3 errata workarounds

From: Linu Cherian
Date: Mon May 08 2017 - 11:16:11 EST


On Sat May 06, 2017 at 12:22:50AM +0200, Robert Richter wrote:
> On 05.05.17 17:38:04, Geetha sowjanya wrote:
> > From: Linu Cherian <linu.cherian@xxxxxxxxxx>
> >
> > Cavium ThunderX2 SMMUv3 implementation has two Silicon Erratas.
> > 1. Errata ID #74
> > SMMU register alias Page 1 is not implemented
> > 2. Errata ID #126
> > SMMU doesnt support unique IRQ lines and also MSI for gerror,
> > eventq and cmdq-sync
> >
> > The following patchset does software workaround for these two erratas.
> >
> > This series is based on patchset.
> > https://www.spinics.net/lists/arm-kernel/msg578443.html
> >
> > Changes from v1:
> > Since the use of MIDR register is rejected and SMMU_IIDR is broken on this
> > silicon, as suggested by Will Deacon modified the patches to use ThunderX2
> > SMMUv3 IORT model number to enable errata workaround.
> >
> > Changes from v2:
> > Updated "Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt" document with
> > new SMMU option used to enable errata workaround.
> >
> > Geetha Sowjanya (1):
> > iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126
> >
> > Linu Cherian (6):
> > iommu/arm-smmu-v3: Introduce smmu option PAGE0_REGS_ONLY for ThunderX2
> > errata#74.
> > iommu/arm-smmu-v3: Do resource size checks based on SMMU option
> > PAGE0_REGS_ONLY
> > ACPICA: IORT: Add Cavium ThunderX2 SMMUv3 model definition.
> > iommu/arm-smmu-v3: For ACPI based device probing, set PAGE0_REGS_ONLY
> > option for ThunderX2 SMMUv3 implementations.
> > ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3
> > model
> > arm64: Documentation: Add Cavium ThunderX2 SMMUv3 erratas
>
> This split into patches does not look reasonable to me. 1 patch only
> for each workaround should be sufficient.
>

* Should we not atleast keep the changes in drivers/acpi/iort.c and
include/acpi/actbl2.h seperate, since they are outside smmuv3 driver ?

* Probably i can merge the below patches,
1. iommu/arm-smmu-v3: Introduce smmu option PAGE0_REGS_ONLY for ThunderX2
errata#74.
2. iommu/arm-smmu-v3: Do resource size checks based on SMMU option
PAGE0_REGS_O

Is that fine ?

Thanks.
--
Linu cherian