Commit 1d9777b9 authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
Browse files

iommu/arm-smmu-v3: Add explicit feature for nesting 



In certain cases we may want to refuse to allow nested translation even
when both stages are implemented, so let's add an explicit feature for
nesting support which we can control in its own right. For now this
merely serves as documentation, but it means a nice convenient check
will be ready and waiting for the future nesting code.

Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Reviewed-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/136c3f4a3a84cc14a5a1978ace57dfd3ed67b688.1683731256.git.robin.murphy@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 309a15cb

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

+4 −0
Original line number Diff line number Diff line
@@ -3674,6 +3674,10 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) 


	smmu->ias = max(smmu->ias, smmu->oas);



	if ((smmu->features & ARM_SMMU_FEAT_TRANS_S1) &&

	    (smmu->features & ARM_SMMU_FEAT_TRANS_S2))

		smmu->features |= ARM_SMMU_FEAT_NESTING;



	arm_smmu_device_iidr_probe(smmu);



	if (arm_smmu_sva_supported(smmu))

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h

+1 −0
Original line number Diff line number Diff line
@@ -645,6 +645,7 @@ struct arm_smmu_device { 
#define ARM_SMMU_FEAT_BTM		(1 << 16)

#define ARM_SMMU_FEAT_SVA		(1 << 17)

#define ARM_SMMU_FEAT_E2H		(1 << 18)

#define ARM_SMMU_FEAT_NESTING		(1 << 19)

	u32				features;



#define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)