Re: [PATCH v4 2/5] remoteproc: qcom: Introduce driver to store pil info in IMEM

From: Bjorn Andersson
Date: Wed Mar 11 2020 - 19:33:01 EST


On Wed 11 Mar 16:25 PDT 2020, Stephen Boyd wrote:

> Quoting Bjorn Andersson (2020-03-10 14:27:28)
> > On Tue 10 Mar 13:29 PDT 2020, Stephen Boyd wrote:
> >
> > > Why can't we search in DT for the
> > > imem node and then find the pil reloc info compatible string on the
> > > first call to this library? Then we don't need an API to see if the
> > > device has probed yet (qcom_pil_info_available)
> >
> > I think this sounds reasonable.
>
> Great!
>
> >
> > > and we can just ioremap
> > > some region of memory that's carved out for this reason. Forcing
> > > everything through the regmap is mostly adding pain.
> > >
> >
> > My concern here was simply that we'll end up ioremapping various small
> > chunks of the imem region 10 (or so) times. But I agree that things
> > would be cleaner here.
>
> Alright. I'd like the ioremap() approach. ioremap() will "do the right
> thing" and reuse mappings if they're already there and overlap in the
> page. So it's OK that the syscon/simple-mfd exists and makes a device,
> etc. etc., but we don't need to care about it. We can just ioremap() the
> area and not worry that the regmap users may have a mapping to the same
> place. This is a dedicated carveout inside IMEM so we're safe from other
> meddling users.

Agreed, thanks for the feedback!

Regards,
Bjorn