RE: [PATCH v2 0/8] Enable PASID for DMA API users

[Tian, Kevin]

> From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> Sent: Tuesday, March 15, 2022 1:07 PM
> 
> Some modern accelerators such as Intel's Data Streaming Accelerator (DSA)
> require PASID in DMA requests to be operational. Specifically, the work
> submissions with ENQCMD on shared work queues require PASIDs. The use
> cases
> include both user DMA with shared virtual addressing (SVA) and in-kernel
> DMA similar to legacy DMA w/o PASID. Here we address the latter.
> 
> DMA mapping API is the de facto standard for in-kernel DMA. However, it
> operates on a per device or Requester ID(RID) basis which is not
> PASID-aware. To leverage DMA API for devices relies on PASIDs, this
> patchset introduces the following APIs
> 
> 1. A driver facing API that enables DMA API PASID usage:
> iommu_enable_pasid_dma(struct device *dev, ioasid_t &pasid);

Should this be called dma_enable_pasid() since it's about DMA API? Doing
so also avoids the driver to include iommu.h.

Thanks
Kevin