Re: [PATCH v4 18/24] iommu/mediatek: Support master use iova over 32bit

[Krzysztof Kozlowski]

On Wed, Nov 11, 2020 at 08:38:32PM +0800, Yong Wu wrote:
> After extending v7s, our pagetable already support iova reach
> 16GB(34bit). the master got the iova via dma_alloc_attrs may reach
> 34bits, but its HW register still is 32bit. then how to set the
> bit32/bit33 iova? this depend on a SMI larb setting(bank_sel).
> 
> we separate whole 16GB iova to four banks:
> bank: 0: 0~4G; 1: 4~8G; 2: 8-12G; 3: 12-16G;
> The bank number is (iova >> 32).
> 
> We will preassign which bank the larbs belong to. currently we don't
> have a interface for master to adjust its bank number.
> 
> Each a bank is a iova_region which is a independent iommu-domain.
> the iova range for each iommu-domain can't cross 4G.
> 
> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> Acked-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> # memory part
> ---
>  drivers/iommu/mtk_iommu.c  | 12 +++++++++---
>  drivers/memory/mtk-smi.c   |  7 +++++++
>  include/soc/mediatek/smi.h |  1 +
>  3 files changed, 17 insertions(+), 3 deletions(-)
> 

Acked-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

Best regards,
Krzysztof