Re: [PATCH v3 2/4] dts: arm64: qcom: sdm845: add SLPI FastRPC support

[Dylan Van Assche <me@dylanvanassche.be>]

Hi Konrad,

On Fri, 2023-03-31 at 04:03 +0200, Konrad Dybcio wrote:
> 
> 
> On 30.03.2023 18:53, Dylan Van Assche wrote:
> > Qualcomm SDM845 SoC features a SLPI DSP which uses FastRPC through
> > an allocated memory region to load files from the host filesystem
> > such as sensor configuration files.
> > 
> > Add a FastRPC node at /dev/fastrpc-sdsp and a DMA region, similar
> > to
> > downstream, to allow userspace to communicate with the SLPI via the
> > FastRPC interface for initializing the sensors on the SLPI.
> > 
> > Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
> > ---
> >  arch/arm64/boot/dts/qcom/sdm845.dtsi | 24 ++++++++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> > 
> > diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > index 3b547cb7aeb8..8ea4944f3ad6 100644
> > --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > @@ -878,6 +878,14 @@ mdata_mem: mpss-metadata {
> >                         size = <0 0x4000>;
> >                         no-map;
> >                 };
> > +
> > +               fastrpc_mem: fastrpc {
> > +                       compatible = "shared-dma-pool";
> > +                       reusable;
> Please move it last to get a nice reverse-Christmas-tree layout.
> 

Will fix in v4.

> > +                       alloc-ranges = <0 0x00000000 0 0xffffffff>;
> Would there be any issues with it starting over (1<<31 - 1)?
> 

You mean a bigger region then, like the whole CMA region then? AFAIK,
the SLPI always use the same region expecting it to be in this range.
However, I cannot confirm more, as I have no insights in the firmware
running on there, this all comes from finding out what it exactly does
on downstream.

> > +                       alignment = <0 0x400000>;
> Please use 0x0 for the 0 here, as it's essentially reg.size with
> size-cells = 2

Will fix in v4.

> 
> > +                       size = <0 0x1000000>;
> Ditto

Will fix in v4.

> 
> > +               };
> >         };
> >  
> >         adsp_pas: remoteproc-adsp {
> > @@ -3344,6 +3352,22 @@ glink-edge {
> >                                 label = "dsps";
> >                                 qcom,remote-pid = <3>;
> >                                 mboxes = <&apss_shared 24>;
> > +
> > +                               fastrpc {
> > +                                       compatible =
> > "qcom,fastrpc";
> > +                                       qcom,glink-channels =
> > "fastrpcglink-apps-dsp";
> > +                                       label = "sdsp";
> > +                                       qcom,non-secure-domain;
> > +                                       qcom,vmids = <0x3 0xF 0x5
> > 0x6>;
> Please use the recently-introduced header and depend on (and
> make a patch atop)
> 
> https://lore.kernel.org/linux-arm-msm/8685b710-b74d-556a-815d-0ffef2b0eeff@linaro.org/T/#t
> 
> Konrad
> 
> > +                                       memory-region =
> > <&fastrpc_mem>;
> > +                                       #address-cells = <1>;
> > +                                       #size-cells = <0>;
> > +
> > +                                       compute-cb@0 {
> > +                                               compatible =
> > "qcom,fastrpc-compute-cb";
> > +                                               reg = <0>;
> > +                                       };
> > +                               };
> >                         };
> >                 };
> >  

Kind regards,
Dylan