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

Yong Wu
2020-12-24T11:27:50Z

On Wed, 2020-12-23 at 17:15 +0900, Tomasz Figa wrote:
> 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?

It is not a really a domain. The address range comes from CCU HW
requirement. That HW can only access this iova range. thus I create a
special iommu domain for it.

>
> 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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