[PATCH RFC 0/4] iommu/arm-smmu-v3: Support shared Stream IDs

Jason Gunthorpe jgg at ziepe.ca
Wed Sep 16 09:10:18 PDT 2026


On Wed, Sep 16, 2026 at 11:12:33PM +0800, Peng Fan (OSS) wrote:
> Some SoCs have a limited number of IOMMU Stream IDs (SIDs) and
> hardware that inherently shares them. For example, the NXP i.MX95
> eDMA controller has 64 channels where each TX/RX pair is assigned
> a single SID by the hardware - the two channel devices are distinct
> from Linux's perspective but present the same SID to the SMMU.

Is that a reflection of poor DT modelling though?

Why must a TX/RX *PAIR* have two platform_devices nodes?

Fix it there and you don't need any of this? Or is there more?

Jason



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