On Mon, 2020-07-20 at 17:16 -0600, Rob Herring wrote: > On Sat, Jul 11, 2020 at 02:48:29PM +0800, Yong Wu wrote: > > This patch adds decriptions for mt8192 IOMMU and SMI. > > > > mt8192 also is MTK IOMMU gen2 which uses ARM Short-Descriptor translation > > table format. The M4U-SMI HW diagram is as below: > > > > EMI > > | > > M4U > > | > > ------------ > > SMI Common > > ------------ > > | > > +-------+------+------+----------------------+-------+ > > | | | | ...... | | > > | | | | | | > > larb0 larb1 larb2 larb4 ...... larb19 larb20 > > disp0 disp1 mdp vdec IPE IPE > > > > All the connections are HW fixed, SW can NOT adjust it. > > > > mt8192 M4U support 0~16GB iova range. we preassign different engines > > into different iova ranges: > > > > domain-id module iova-range larbs > > 0 disp 0 ~ 4G larb0/1 > > 1 vcodec 4G ~ 8G larb4/5/7 > > 2 cam/mdp 8G ~ 12G larb2/9/11/13/14/16/17/18/19/20 > > 3 CCU0 0x4000_0000 ~ 0x43ff_ffff larb13: port 9/10 > > 4 CCU1 0x4400_0000 ~ 0x47ff_ffff larb14: port 4/5 > > You probably want to use dma-ranges for defining these > address restrictions. Yes. Please see the commit message of [18/21] in this patchset. > > How is the domain-id used or needed? Here we assign different larb/ports in different iova ranges. In the iommu driver, we will list the iova ranges as above and use the domain-id to get the detailed iova range, then create a iommu domain for each a iova range. For the iommu masters, it only need use its special port in its dtsi node, then the iova got from dma_alloc_attrs for that device will locate in the special iova ranges. > > Rob > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-mediatek
