Re: [RFC PATCH v1 04/15] iommu: Add DOMAIN_ATTR_PTBASE

[Joerg Roedel]

Hi Jordan,

On Mon, Mar 18, 2019 at 08:19:12AM -0600, Jordan Crouse wrote:
> Adreno GPUs can an internal mechanism to switch the pagetable address in the
> attached arm-smmu v2 IOMMU so that each individual rendering process can have
> their own pagetable. The driver uses iommu_map and iommu_unmap to write
> the pagetable but the address for each individual pagetable needs to be queried
> so it can be sent to the hardware. You can see the driver specific code that
> does this here:

Okay, thanks for the explanation. I still don't like it, but it is
probably better putting gpu-specfic context-switch logic into the iommu
driver, so I guess this is okay.


Regards,

	Joerg