On Mon, Jan 11, 2021 at 07:18:41PM +0800, Yong Wu wrote:

This patch mainly adds support for mt8192 Multimedia 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.

Comparing with the preview SoC, this patchset mainly adds two new functions:
a) add iova 34 bits support.
b) add multi domains support since several HW has the special iova
region requirement.

This is looking good and I'd really like to see it merged, especially as it
has changes to the io-pgtable code. Please could you post a new version ASAP
to address the comments on patches 6 and 7?

Will