Re: [PATCH 3/3] iommu/ipmmu-vmsa: Hook up r8a7796 DT matching code

[Magnus Damm]

Hi Laurent,

On Wed, Jun 8, 2016 at 5:48 PM, Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
> Hi Geert,
>
> On Wednesday 08 Jun 2016 09:04:17 Geert Uytterhoeven wrote:
>> On Wed, Jun 8, 2016 at 2:18 AM, Laurent Pinchart wrote:
>> >> --- 0031/drivers/iommu/ipmmu-vmsa.c
>> >> +++ work/drivers/iommu/ipmmu-vmsa.c   2016-06-06 11:19:40.210607110 +0900
>> >> @@ -1074,7 +1074,7 @@ static const struct ipmmu_features ipmmu
>> >>       .twobit_imttbcr_sl0 = false,
>  >>  };
>> >>
>> >> -static const struct ipmmu_features ipmmu_features_r8a7795 = {
>> >> +static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
>> >>       .use_ns_alias_offset = false,
>> >>       .has_cache_leaf_nodes = true,
>> >>       .has_eight_ctx = true,
>> >> @@ -1088,7 +1088,10 @@ static const struct of_device_id ipmmu_o
>> >>               .data = &ipmmu_features_default,
>> >>       }, {
>> >>               .compatible = "renesas,ipmmu-r8a7795",
>> >> -             .data = &ipmmu_features_r8a7795,
>> >> +             .data = &ipmmu_features_rcar_gen3,
>> >> +     }, {
>> >> +             .compatible = "renesas,ipmmu-r8a7796",
>> >> +             .data = &ipmmu_features_rcar_gen3,
>> >>       }, {
>> >>               /* Terminator */
>> >>       },
>> >> @@ -1268,6 +1271,8 @@ IOMMU_OF_DECLARE(ipmmu_vmsa_iommu_of, "r
>> >>                ipmmu_vmsa_iommu_of_setup);
>> >>  IOMMU_OF_DECLARE(ipmmu_r8a7795_iommu_of, "renesas,ipmmu-r8a7795",
>> >>                ipmmu_vmsa_iommu_of_setup);
>> >> +IOMMU_OF_DECLARE(ipmmu_r8a7796_iommu_of, "renesas,ipmmu-r8a7796",
>> >> +              ipmmu_vmsa_iommu_of_setup);
>> >
>> > How about a Gen3 generic compatible string in addition to the SoC-specific
>> > ones ?
>>
>> Do we want to specify the number of utlbs here?
>> Does it differ between r8a7795, r8a7796, and future members?
>
> It differs between IPMMU instances on a given SoC, so if we want to specify it
> it should be a DT property.

Can you please point out which documentation that says it varies with
IPMMU instance?

Based on IMUCTRn register description "H3-ES1" has 0-31 range while
"Others" have 0-47.

Thanks,

/ magnus