Re: [PATCH v2 1/3] arm64: dts: qcom: sdm630/660: Add CDSP-related nodes

[Nickolay Goppen <setotau@mainlining.org>]

24.11.2025 18:02, Nickolay Goppen пишет:
>
> 23.11.2025 13:51, Nickolay Goppen пишет:
>>
>> 21.11.2025 15:09, Dmitry Baryshkov пишет:
>>> On Fri, Nov 21, 2025 at 01:41:21PM +0530, Ekansh Gupta wrote:
>>>>
>>>> On 11/20/2025 5:17 PM, Konrad Dybcio wrote:
>>>>> On 11/20/25 11:54 AM, Ekansh Gupta wrote:
>>>>>> On 11/20/2025 1:27 PM, Nickolay Goppen wrote:
>>>>>>> 20.11.2025 07:55, Ekansh Gupta пишет:
>>>>>>>> On 11/20/2025 1:58 AM, Srinivas Kandagatla wrote:
>>>>>>>>> On 11/12/25 1:52 PM, Konrad Dybcio wrote:
>>>>>>>>>> On 11/10/25 6:41 PM, Srinivas Kandagatla wrote:
>>>>>>>>>>> On 11/3/25 12:52 PM, Konrad Dybcio wrote:
>>>>>>>>>>>> On 10/31/25 12:30 PM, Nickolay Goppen wrote:
>>>>>>>>>>>>> 24.10.2025 16:58, Nickolay Goppen пишет:
>>>>>>>>>>>>>> 24.10.2025 11:28, Konrad Dybcio пишет:
>>>>>>>>>>>>>>> On 10/23/25 9:51 PM, Nickolay Goppen wrote:
>>>>>>>>>>>>>>>> In order to enable CDSP support for SDM660 SoC:
>>>>>>>>>>>>>>>>     * add shared memory p2p nodes for CDSP
>>>>>>>>>>>>>>>>     * add CDSP-specific smmu node
>>>>>>>>>>>>>>>>     * add CDSP peripheral image loader node
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Memory region for CDSP in SDM660 occupies the same spot as
>>>>>>>>>>>>>>>> TZ buffer mem defined in sdm630.dtsi (which does not 
>>>>>>>>>>>>>>>> have CDSP).
>>>>>>>>>>>>>>>> In sdm660.dtsi replace buffer_mem inherited from SDM630 
>>>>>>>>>>>>>>>> with
>>>>>>>>>>>>>>>> cdsp_region, which is also larger in size.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> SDM636 also doesn't have CDSP, so remove inherited from 
>>>>>>>>>>>>>>>> sdm660.dtsi
>>>>>>>>>>>>>>>> related nodes and add buffer_mem back.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Signed-off-by: Nickolay Goppen <setotau@mainlining.org>
>>>>>>>>>>>>>>>> ---
>>>>>>>>>>>>>>> [...]
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> + label = "turing";
>>>>>>>>>>>>>>> "cdsp"
>>>>>>>>>>>>>> Ok, I'll change this in the next revision.
>>>>>>>>>>>>>>>> + mboxes = <&apcs_glb 29>;
>>>>>>>>>>>>>>>> +            qcom,remote-pid = <5>;
>>>>>>>>>>>>>>>> +
>>>>>>>>>>>>>>>> +            fastrpc {
>>>>>>>>>>>>>>>> +                compatible = "qcom,fastrpc";
>>>>>>>>>>>>>>>> +                qcom,glink-channels = 
>>>>>>>>>>>>>>>> "fastrpcglink-apps-dsp";
>>>>>>>>>>>>>>>> +                label = "cdsp";
>>>>>>>>>>>>>>>> + qcom,non-secure-domain;
>>>>>>>>>>>>>>> This shouldn't matter, both a secure and a non-secure 
>>>>>>>>>>>>>>> device is
>>>>>>>>>>>>>>> created for CDSP
>>>>>>>>>>>>>> I've added this property, because it is used in other 
>>>>>>>>>>>>>> SoC's, such as SDM845 and SM6115 for both ADSP and CDSP
>>>>>>>>>>>>> Is this property not neccessary anymore?
>>>>>>>>>>>> +Srini?
>>>>>>>>>>> That is true, we do not require this for CDSP, as CDSP 
>>>>>>>>>>> allows both
>>>>>>>>>>> unsigned and signed loading, we create both secured and 
>>>>>>>>>>> non-secure node
>>>>>>>>>>> by default. May be we can provide that clarity in yaml 
>>>>>>>>>>> bindings so that
>>>>>>>>>>> it gets caught during dtb checks.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> However in ADSP case, we only support singed modules, due to 
>>>>>>>>>>> historical
>>>>>>>>>>> reasons how this driver evolved over years, we have this 
>>>>>>>>>>> flag to allow
>>>>>>>>>>> compatiblity for such users.
>>>>>>>>>> Does that mean that we can only load signed modules on the 
>>>>>>>>>> ADSP, but
>>>>>>>>>> the driver behavior was previously such that unsigned modules 
>>>>>>>>>> were
>>>>>>>>>> allowed (which was presumably fine on devboards, but not on 
>>>>>>>>>> fused
>>>>>>>>>> devices)?
>>>>>>>>> Yes, its true that we allowed full access to adsp device nodes 
>>>>>>>>> when we
>>>>>>>>> first started upstreaming fastrpc driver.
>>>>>>>>>
>>>>>>>>> irrespective of the board only signed modules are supported on 
>>>>>>>>> the ADSP.
>>>>>>>>> I think there was one version of SoC i think 8016 or some 
>>>>>>>>> older one
>>>>>>>>> which had adsp with hvx which can load unsigned modules for 
>>>>>>>>> compute
>>>>>>>>> usecase only.
>>>>>>>>>
>>>>>>>>> I have added @Ekansh for more clarity.
>>>>>>>>>
>>>>>>>>> --srini
>>>>>>>> For all the available platforms, ADSP supports only signed 
>>>>>>>> modules. Unsigned
>>>>>>>> modules(as well as signed) are supported by CDSP and GDSP 
>>>>>>>> subsystems.
>>>>>>>>
>>>>>>>> qcom,non-secure-domain property marks the corresponding DSP as 
>>>>>>>> non-secure DSP.
>>>>>>>> The implications of adding this property would be the following:
>>>>>>>> on ADSP, SDSP, MDSP:
>>>>>>>> - Only non-secure device node(/dev/fastrpc-Xdsp) is created.
>>>>>>>> - Non-secure device node can be used for signed DSP PD offload.
>>>>>>>>
>>>>>>>> on CDSP, GDSP:
>>>>>>>> - Both secure(/dev/fastrpc-Xdsp-secure) and 
>>>>>>>> non-secure(/dev/fastrpc-Xdsp) devices
>>>>>>>>     are created, regardless of this property.
>>>>>>>> - Both the nodes can be used for signed and unsigned DSP PD 
>>>>>>>> offload.
>>>>>>>>
>>>>>>>> Note: If the property is not added for CDSP/GDSP, only secure 
>>>>>>>> device node can
>>>>>>>> be used for signed PD offload, if non-secure device is used, 
>>>>>>>> the request gets
>>>>>>>> rejected[1].
>>>>>>>>
>>>>>>>> [1] 
>>>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/misc/fastrpc.c#n1245
>>>>>>>>
>>>>>>>> //Ekansh
>>>>>>> Does this mean that the qcom,non-secure-domain property should 
>>>>>>> be dropped from both nodes?
>>>>>> I checked again and found that unsigned module support for CDSP is
>>>>>> not available on this platform. Given this, the safest approach 
>>>>>> would
>>>>>> be to add the property for both ADSP and CDSP, ensuring that all
>>>>>> created device nodes can be used for signed PD offload. I can 
>>>>>> provide
>>>>> The property allows *unsigned* PD offload though
>>>> I don't think I can directly relate this property to unsigned PD 
>>>> offload. This is just
>>>> defining what type of device node will be created and whether the 
>>>> channel is secure
>>>> or not. There is a possibility of making unsigned PD request(on 
>>>> CDSP/GDSP) irrespective
>>>> of whether this property is added or not. If DSP does not support 
>>>> unsigned offload, it
>>>> should return failures for such requests.
>>> Which part of the hardware and/or firmware interface does it define? If
>>> it simply declared Linux behaviour, it is incorrect and probably should
>>> be dropped.
>> I still don't understand, do I need this property or not?
>
> I've began testing the FastRPC on CDSP and the command
>
> sudo fastrpc_test -d 3 -U 1 -t linux -a v68
> has caused the following errors:
>
> [   60.810545] arm-smmu 5180000.iommu: Unhandled context fault: 
> fsr=0x402, iova=0xfffff000, fsynr=0x1, cbfrsynra=0x6, cb=3
> [   60.810588] arm-smmu 5180000.iommu: FSR    = 00000402 [Format=2 
> TF], SID=0x6
> [   60.810603] arm-smmu 5180000.iommu: FSYNR0 = 00000001 [S1CBNDX=0 
> PLVL=1]
> [   60.815657] qcom_q6v5_pas 1a300000.remoteproc: fatal error 
> received: :0:EX:kernel:0:frpck_0_0:77:PC=c0117de0
> [   60.815684] remoteproc remoteproc2: crash detected in cdsp: type 
> fatal error
> [   60.815738] remoteproc remoteproc2: handling crash #1 in cdsp
> [   60.815754] remoteproc remoteproc2: recovering cdsp
> [   60.819267] (NULL device *): Error: dsp information is incorrect 
> err: -32
>
How to debug such issues?
>
>>>>>> a more definitive recommendation once I know the specific use cases
>>>>>> you plan to run.
>>>>> Why would the usecase affect this?
>>>> I'm saying this as per past discussions where some application was 
>>>> relying on non-secure
>>>> device node on some old platform(on postmarketOS)[1] and having 
>>>> this property in place.
>>>> So if similar usecase is being enabled here, the property might be 
>>>> required[1].
>>> DT files are not usecase-based.
>>>
>>>> [1] https://lkml.org/lkml/2024/8/15/117
>>
-- 
Best regards,
Nickolay