> -----Original Message----- > From: iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx [mailto:iommu- > bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Robin Murphy > Sent: Friday, December 16, 2016 18:49 > To: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx > Cc: mark.rutland@xxxxxxx; will.deacon@xxxxxxx; Stuart Yoder > <stuart.yoder@xxxxxxx> > Subject: [RFC PATCH] iommu/arm-smmu: Add global SMR masking property > > The current SMR masking support using a 2-cell iommu-specifier is > primarily intended to handle individual masters with large and/or > complex Stream ID assignments; it quickly gets a bit clunky in other SMR > use-cases where we just want to consistently mask out the same part of > every Stream ID (e.g. for MMU-500 configurations where the appended TBU > number gets in the way unnecessarily). Let's add a new property to allow > a single global mask value to better fit the latter situation. > > CC: Stuart Yoder <stuart.yoder@xxxxxxx> Tested-by: Nipun Gupta <nipun.gupta@xxxxxxx> > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> > --- > > Compile-tested only... > > Documentation/devicetree/bindings/iommu/arm,smmu.txt | 8 ++++++++ > drivers/iommu/arm-smmu.c | 4 +++- > 2 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt > b/Documentation/devicetree/bindings/iommu/arm,smmu.txt > index e862d1485205..98f5cbe5fdb4 100644 > --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt > +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt > @@ -60,6 +60,14 @@ conditions. > aliases of secure registers have to be used during > SMMU configuration. > > +- stream-match-mask : Specifies a fixed SMR mask value to combine with > + the Stream ID value from every iommu-specifier. This > + may be used instead of an "#iommu-cells" value of 2 > + when there is no need for per-master SMR masks, but > + it is still desired to mask some portion of every > + Stream ID (e.g. for certain MMU-500 configurations > + given globally unique external IDs). > + > ** Deprecated properties: > > - mmu-masters (deprecated in favour of the generic "iommus" binding) : > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 8f7281444551..f1abcb7dde36 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -1534,13 +1534,15 @@ static int arm_smmu_domain_set_attr(struct > iommu_domain *domain, > > static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args) > { > - u32 fwid = 0; > + u32 mask, fwid = 0; > > if (args->args_count > 0) > fwid |= (u16)args->args[0]; > > if (args->args_count > 1) > fwid |= (u16)args->args[1] << SMR_MASK_SHIFT; > + else if (!of_property_read_u32(args->np, "stream-match-mask", > &mask)) > + fwid |= (u16)mask << SMR_MASK_SHIFT; > > return iommu_fwspec_add_ids(dev, &fwid, 1); > } > -- > 2.10.2.dirty > > _______________________________________________ > iommu mailing list > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > https://lists.linuxfoundation.org/mailman/listinfo/iommu -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
