On Tue, Oct 08, 2013 at 11:10:07AM -0400, Will Deacon wrote: > On Tue, Oct 08, 2013 at 10:27:22AM +0100, Andreas Herrmann wrote: > > Ie. use a mask based on smr_mask_bits to map all stream IDs of an SMMU > > to one context. > > > > This behaviour is controlled per SMMU node with DT property > > "arm,smmu-mask-stream-ids" and is only allowed if just a single master > > is attached to an SMMU. If the option is specified, all stream-ids > > that are provided in DT for the single master have no relevance. > > > > This is useful/convenient if a master has more than 8 stream-ids or if > > not all stream-ids are known for a master device. > > Hmmm, this really scares me. What's the use-case? I worry about people > inadvertently putting devices into an iommu domain because they happen to be > included in a mask. Your solution seems to be targetting a single master > with lots of IDs -- is this a PCI RC?
No, it's the sata device. It has 0xf as smr_mask_bits. But it's just one device and it (usually) should be mapped to one context -- no matter how many StreamIDs are really used. (PCI RC has also 0xf but there it's clear there can be multiple devices and the masking should not be done.) Andreas _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
