Re: [PATCH v5 04/27] dt-bindings: memory: mediatek: Add domain definition

[Tomasz Figa <tfiga@chromium.org>]

Hi Yong,

On Wed, Dec 09, 2020 at 04:00:39PM +0800, Yong Wu wrote:
> In the latest SoC, there are several HW IP require a sepecial iova
> range, mainly CCU and VPU has this requirement. Take CCU as a example,
> CCU require its iova locate in the range(0x4000_0000 ~ 0x43ff_ffff).

Is this really a domain? Does the address range come from the design of
the IOMMU?

Best regards,
Tomasz

> 
> In this patch we add a domain definition for the special port. In the
> example of CCU, If we preassign CCU port in domain1, then iommu driver
> will prepare a independent iommu domain of the special iova range for it,
> then the iova got from dma_alloc_attrs(ccu-dev) will locate in its special
> range.
> 
> This is a preparing patch for multi-domain support.
> 
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
> Acked-by: Rob Herring <robh@kernel.org>
> ---
>  include/dt-bindings/memory/mtk-smi-larb-port.h | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/include/dt-bindings/memory/mtk-smi-larb-port.h b/include/dt-bindings/memory/mtk-smi-larb-port.h
> index 7d64103209af..2d4c973c174f 100644
> --- a/include/dt-bindings/memory/mtk-smi-larb-port.h
> +++ b/include/dt-bindings/memory/mtk-smi-larb-port.h
> @@ -7,9 +7,16 @@
>  #define __DT_BINDINGS_MEMORY_MTK_MEMORY_PORT_H_
>  
>  #define MTK_LARB_NR_MAX			32
> +#define MTK_M4U_DOM_NR_MAX		8
> +
> +#define MTK_M4U_DOM_ID(domid, larb, port)	\
> +	(((domid) & 0x7) << 16 | (((larb) & 0x1f) << 5) | ((port) & 0x1f))
> +
> +/* The default dom id is 0. */
> +#define MTK_M4U_ID(larb, port)		MTK_M4U_DOM_ID(0, larb, port)
>  
> -#define MTK_M4U_ID(larb, port)		(((larb) << 5) | (port))
>  #define MTK_M4U_TO_LARB(id)		(((id) >> 5) & 0x1f)
>  #define MTK_M4U_TO_PORT(id)		((id) & 0x1f)
> +#define MTK_M4U_TO_DOM(id)		(((id) >> 16) & 0x7)
>  
>  #endif
> -- 
> 2.18.0
> 
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