Hi Yong,

2015-05-15 11:43 GMT+02:00 Yong Wu [off-list ref]:

  This patch adds support for m4u(Multimedia Memory Management Unit),
Currently it only support the m4u with 2 levels of page table on mt8173.

  It is based on Robin Murphy's arm64: IOMMU-backed DMA mapping[1].

  Please check the hardware block diagram of Mediatek IOMMU.

              EMI (External Memory Interface)
               |
              m4u (Multimedia Memory Management Unit)
               |
              smi (Smart Multimedia Interface)
               |
        +---------------+-------
        |               |
        |               |
    vdec larb       disp larb      ... SoCs have different local arbiter(larb).
        |               |
        |               |
   +----+----+    +-----+-----+
   |    |    |    |     |     |    ...
   |    |    |    |     |     |    ...
   |    |    |    |     |     |    ...
  MC   PP   VLD  OVL0 RDMA0 WDMA0  ... There are different ports in each larb.

  Normally we specify a local arbiter(larb) for each multimedia hardware like
display, video decode, video encode and camera. And there are different ports in
each larb. Take a example, there are some ports like MC, PP, UFO, VLD, AVC_MV,
PRED_RD, PRED_WR in video larb, all the ports are according to the video hardware.

  From the diagram, all the multimedia module connect with m4u via smi.
SMI is responsible to enable/disable iommu and control the clocks for each local
arbiter. If we should enable the iommu of video decode, it should config the
video's ports. And if the video hardware work wether enable/disable iommu,
it should enable the clock of its larb's clock. So we add a special driver for smi.

[1] http://lists.linuxfoundation.org/pipermail/iommu/2015-February/012236.html

v2:
-add arm short descriptor support.
-seperate smi common from smi and change the clock-names according
 to smi HW.
-delete the hardcode of the port-names in mt8173.
 replace this with larb-portes-nr in dtsi.
-fix some coding style issues.

v1:
http://lists.infradead.org/pipermail/linux-mediatek/2015-March/000058.html

Yong Wu (6):
  dt-bindings: iommu: Add binding for mediatek IOMMU
  dt-bindings: mediatek: Add smi dts binding
  iommu: add ARM short descriptor page table allocator.
  iommu/mediatek: Add mt8173 IOMMU driver
  soc: mediatek: Add SMI driver
  dts: mt8173: Add iommu/smi nodes for mt8173

Some general comments.
It seems that your patches are not based on v4.1.-rc1, can you please
fix this in the next version, they don't apply cleanly.
Please use the checkpatch script before sending the next version, I
had some whitespace errors reported when applying the series.

Thanks,
Matthias

-- 
motzblog.wordpress.com