Re: [PATCH v6 13/22] iommu/mediatek: Add mt8183 IOMMU support

From: Evan Green
Date: Tue Feb 19 2019 - 18:37:56 EST


On Sun, Feb 17, 2019 at 1:08 AM Yong Wu <yong.wu@xxxxxxxxxxxx> wrote:
>
> The M4U IP blocks in mt8183 is MediaTek's generation2 M4U which use
> the ARM Short-descriptor like mt8173, and most of the HW registers
> are the same.
>
> Here list main differences between mt8183 and mt8173/mt2712:
> 1) mt8183 has only one M4U HW like mt8173 while mt2712 has two.
> 2) mt8183 don't have the "bclk" clock, it use the EMI clock instead.
> 3) mt8183 can support the dram over 4GB, but it doesn't call this "4GB
> mode".
> 4) mt8183 pgtable base register(0x0) extend bit[1:0] which represent
> the bit[33:32] in the physical address of the pgtable base, But the
> standard ttbr0[1] means the S bit which is enabled defaultly, Hence,
> we add a mask.
> 5) mt8183 HW has a GALS modules, SMI should enable "has_gals" support.
> 6) mt8183 need reset_axi like mt8173.
> 7) the larb-id in smi-common is remapped. M4U should add its larbid_remap.
>
> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>

Reviewed-by: Evan Green <evgreen@xxxxxxxxxxxx>