Re: [PATCH v8 3/5] iommu/arm-smmu: introduction of ACTLR for custom prefetcher settings

[Bibek Kumar Patro]

On 1/18/2024 11:25 PM, Konrad Dybcio wrote:
> On 1/16/24 16:04, Bibek Kumar Patro wrote:
> > Currently in Qualcomm  SoCs the default prefetch is set to 1 which allows
> > the TLB to fetch just the next page table. MMU-500 features ACTLR
> > register which is implementation defined and is used for Qualcomm SoCs
> > to have a custom prefetch setting enabling TLB to prefetch the next set
> > of page tables accordingly allowing for faster translations.
> >
> > ACTLR value is unique for each SMR (Stream matching register) and stored
> > in a pre-populated table. This value is set to the register during
> > context bank initialisation.
> >
> > Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
>
> Since it's your idea with Dmitry's review suggestions, I don't think
> this tag makes sense.
>
> It's normally used for situations like:
>
> Colleague X: "Hey Bibek, I noticed x broke on y, can you fix it?"
> "Sure!" <proceeds to make a commit with suggested-by Colleague X>

Got it, thanks for the inputs. Will remove this tag as it won't make 
sense in this case as explained by you.

> Just a nit below:
>
> > +struct actlr_config {
> > +    u16 sid;
> > +    u16 mask;
> > +    u32 actlr;
> > +};
>
> This, can go here, in the header:

Sure, Noted. Will add this to the header.
Initially made it local, since it is only being used
in the tables.

Thanks,
Bibek

> > +struct actlr_config;
> > +
> > +struct actlr_variant {
> > +    const resource_size_t io_start;
> > +    const struct actlr_config * const actlrcfg;
> > +    const size_t num_actlrcfg;
> > +};
> > +
>
> Otherwise, this looks good!
>
> Konrad