Re: [PATCH 0/4] iommu: M1 Pro/Max DART support

[Janne Grunau]

Hej,

On 2021-11-17 22:15:05 +0100, Sven Peter wrote:
> 
> This is a fairly brief series to add support for the DARTs present in the
> M1 Pro/Max. They have two differences that make them incompatible with
> those in the M1:
> 
>   - the physical addresses are shifted left by 4 bits and and have 2 more
>     bits inside the PTE entries
>   - the subpage protection feature is now mandatory. For Linux we can
>     just configure it to always allow access to the entire page.
> 
> Note that this needs a fix to the core pagetable code. Hector already
> sent a first version separately to the mailing list since the problem
> is (at least in theory) also present on other SoCs using the LPAE format
> with a large physical address space [1].
> 
> Sven
> 
> [1] https://lore.kernel.org/linux-iommu/a2b45243-7e0a-a2ac-4e14-5256a3e7abb4@xxxxxxx/T/#t
> 
> Sven Peter (4):
>   dt-bindings: iommu: dart: add t6000 compatible
>   iommu/io-pgtable: Add DART subpage protection support
>   iommu/io-pgtable: Add DART PTE support for t6000
>   iommu: dart: Support t6000 variant
> 
>  .../devicetree/bindings/iommu/apple,dart.yaml |  4 +-
>  drivers/iommu/apple-dart.c                    | 19 ++++++++-
>  drivers/iommu/io-pgtable-arm.c                | 40 ++++++++++++++++++-
>  include/linux/io-pgtable.h                    |  2 +
>  4 files changed, 61 insertions(+), 4 deletions(-)

Whole series tested on M1 Max. Feel free to add
Tested-by: Janne Grunau <j@xxxxxxxxxx>

best
Janne