Re: [PATCH v7 6/6] remoteproc: qcom: enable in-kernel PD mapper

[Chris Lew <quic_clew@quicinc.com>]

On 4/26/2024 6:36 PM, Dmitry Baryshkov wrote:
> On Sat, 27 Apr 2024 at 04:03, Chris Lew <quic_clew@quicinc.com> wrote:
>>
>>
>>
>> On 4/24/2024 2:28 AM, Dmitry Baryshkov wrote:
>>> diff --git a/drivers/remoteproc/qcom_q6v5_adsp.c b/drivers/remoteproc/qcom_q6v5_adsp.c
>>> index 1d24c9b656a8..02d0c626b03b 100644
>>> --- a/drivers/remoteproc/qcom_q6v5_adsp.c
>>> +++ b/drivers/remoteproc/qcom_q6v5_adsp.c
>>> @@ -23,6 +23,7 @@
>>>    #include <linux/remoteproc.h>
>>>    #include <linux/reset.h>
>>>    #include <linux/soc/qcom/mdt_loader.h>
>>> +#include <linux/soc/qcom/pd_mapper.h>
>>>    #include <linux/soc/qcom/smem.h>
>>>    #include <linux/soc/qcom/smem_state.h>
>>>
>>> @@ -375,10 +376,14 @@ static int adsp_start(struct rproc *rproc)
>>>        int ret;
>>>        unsigned int val;
>>>
>>> -     ret = qcom_q6v5_prepare(&adsp->q6v5);
>>> +     ret = qcom_pdm_get();
>>>        if (ret)
>>>                return ret;
>>
>> Would it make sense to try and model this as a rproc subdev? This
>> section of the remoteproc code seems to be focused on making specific
>> calls to setup and enable hardware resources, where as pd mapper is
>> software.
>>
>> sysmon and ssr are also purely software and they are modeled as subdevs
>> in qcom_common. I'm not an expert on remoteproc organization but this
>> was just a thought.
> 
> Well, the issue is that the pd-mapper is a global, not a per-remoteproc instance
> 

Both sysmon and ssr have some kind of global states that they manage 
too. Each subdev functionality tends to be a mix of per-remoteproc 
instance management and global state management.

If pd-mapper was completely global, pd-mapper would be able to 
instantiate by itself. Instead, instantiation is dependent on each 
remoteproc instance properly getting and putting references.

The pdm subdev could manage the references to pd-mapper for that 
remoteproc instance.

On the other hand, I think Bjorn recommended this could be moved to 
probe time in v4. The v4 version was doing the reinitialization-dance, 
but I think the recommendation could still apply to this version.

>>
>> Thanks!
>> Chris
>>
>>>
>>> +     ret = qcom_q6v5_prepare(&adsp->q6v5);
>>> +     if (ret)
>>> +             goto put_pdm;
>>> +
>>>        ret = adsp_map_carveout(rproc);
>>>        if (ret) {
>>>                dev_err(adsp->dev, "ADSP smmu mapping failed\n");
>>> @@ -446,6 +451,8 @@ static int adsp_start(struct rproc *rproc)
>>>        adsp_unmap_carveout(rproc);
>>>    disable_irqs:
>>>        qcom_q6v5_unprepare(&adsp->q6v5);
>>> +put_pdm:
>>> +     qcom_pdm_release();
>>>
>>>        return ret;
>>>    }
>>
> 
>